pgbench.c

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/*
 * pgbench.c
 *
 * A simple benchmark program for PostgreSQL
 * Originally written by Tatsuo Ishii and enhanced by many contributors.
 *
 * src/bin/pgbench/pgbench.c
 * Copyright (c) 2000-2024, PostgreSQL Global Development Group
 * ALL RIGHTS RESERVED;
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without a written agreement
 * is hereby granted, provided that the above copyright notice and this
 * paragraph and the following two paragraphs appear in all copies.
 *
 * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
 * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
 * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 */
 
#if defined(WIN32) && FD_SETSIZE < 1024
#error FD_SETSIZE needs to have been increased
#endif
 
#include "postgres_fe.h"
 
#include <ctype.h>
#include <float.h>
#include <limits.h>
#include <math.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <sys/resource.h>       /* for getrlimit */
 
/* For testing, PGBENCH_USE_SELECT can be defined to force use of that code */
#if defined(HAVE_PPOLL) && !defined(PGBENCH_USE_SELECT)
#define POLL_USING_PPOLL
#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#else                           /* no ppoll(), so use select() */
#define POLL_USING_SELECT
#include <sys/select.h>
#endif
 
#include "common/int.h"
#include "common/logging.h"
#include "common/pg_prng.h"
#include "common/string.h"
#include "common/username.h"
#include "fe_utils/cancel.h"
#include "fe_utils/conditional.h"
#include "fe_utils/option_utils.h"
#include "fe_utils/string_utils.h"
#include "getopt_long.h"
#include "libpq-fe.h"
#include "pgbench.h"
#include "port/pg_bitutils.h"
#include "portability/instr_time.h"
 
/* X/Open (XSI) requires <math.h> to provide M_PI, but core POSIX does not */
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
 
#define ERRCODE_T_R_SERIALIZATION_FAILURE  "40001"
#define ERRCODE_T_R_DEADLOCK_DETECTED  "40P01"
#define ERRCODE_UNDEFINED_TABLE  "42P01"
 
/*
 * Hashing constants
 */
#define FNV_PRIME           UINT64CONST(0x100000001b3)
#define FNV_OFFSET_BASIS    UINT64CONST(0xcbf29ce484222325)
#define MM2_MUL             UINT64CONST(0xc6a4a7935bd1e995)
#define MM2_MUL_TIMES_8     UINT64CONST(0x35253c9ade8f4ca8)
#define MM2_ROT             47
 
/*
 * Multi-platform socket set implementations
 */
 
#ifdef POLL_USING_PPOLL
#define SOCKET_WAIT_METHOD "ppoll"
 
typedef struct socket_set
{
    int         maxfds;         /* allocated length of pollfds[] array */
    int         curfds;         /* number currently in use */
    struct pollfd pollfds[FLEXIBLE_ARRAY_MEMBER];
} socket_set;
 
#endif                          /* POLL_USING_PPOLL */
 
#ifdef POLL_USING_SELECT
#define SOCKET_WAIT_METHOD "select"
 
typedef struct socket_set
{
    int         maxfd;          /* largest FD currently set in fds */
    fd_set      fds;
} socket_set;
 
#endif                          /* POLL_USING_SELECT */
 
/*
 * Multi-platform thread implementations
 */
 
#ifdef WIN32
/* Use Windows threads */
#include <windows.h>
#define GETERRNO() (_dosmaperr(GetLastError()), errno)
#define THREAD_T HANDLE
#define THREAD_FUNC_RETURN_TYPE unsigned
#define THREAD_FUNC_RETURN return 0
#define THREAD_FUNC_CC __stdcall
#define THREAD_CREATE(handle, function, arg) \
    ((*(handle) = (HANDLE) _beginthreadex(NULL, 0, (function), (arg), 0, NULL)) == 0 ? errno : 0)
#define THREAD_JOIN(handle) \
    (WaitForSingleObject(handle, INFINITE) != WAIT_OBJECT_0 ? \
    GETERRNO() : CloseHandle(handle) ? 0 : GETERRNO())
#define THREAD_BARRIER_T SYNCHRONIZATION_BARRIER
#define THREAD_BARRIER_INIT(barrier, n) \
    (InitializeSynchronizationBarrier((barrier), (n), 0) ? 0 : GETERRNO())
#define THREAD_BARRIER_WAIT(barrier) \
    EnterSynchronizationBarrier((barrier), \
                                SYNCHRONIZATION_BARRIER_FLAGS_BLOCK_ONLY)
#define THREAD_BARRIER_DESTROY(barrier)
#else
/* Use POSIX threads */
#include "port/pg_pthread.h"
#define THREAD_T pthread_t
#define THREAD_FUNC_RETURN_TYPE void *
#define THREAD_FUNC_RETURN return NULL
#define THREAD_FUNC_CC
#define THREAD_CREATE(handle, function, arg) \
    pthread_create((handle), NULL, (function), (arg))
#define THREAD_JOIN(handle) \
    pthread_join((handle), NULL)
#define THREAD_BARRIER_T pthread_barrier_t
#define THREAD_BARRIER_INIT(barrier, n) \
    pthread_barrier_init((barrier), NULL, (n))
#define THREAD_BARRIER_WAIT(barrier) pthread_barrier_wait((barrier))
#define THREAD_BARRIER_DESTROY(barrier) pthread_barrier_destroy((barrier))
#endif
 
 
/********************************************************************
 * some configurable parameters */
 
#define DEFAULT_INIT_STEPS "dtgvp"  /* default -I setting */
#define ALL_INIT_STEPS "dtgGvpf"    /* all possible steps */
 
#define LOG_STEP_SECONDS    5   /* seconds between log messages */
#define DEFAULT_NXACTS  10      /* default nxacts */
 
#define MIN_GAUSSIAN_PARAM      2.0 /* minimum parameter for gauss */
 
#define MIN_ZIPFIAN_PARAM       1.001   /* minimum parameter for zipfian */
#define MAX_ZIPFIAN_PARAM       1000.0  /* maximum parameter for zipfian */
 
static int  nxacts = 0;         /* number of transactions per client */
static int  duration = 0;       /* duration in seconds */
static int64 end_time = 0;      /* when to stop in micro seconds, under -T */
 
/*
 * scaling factor. for example, scale = 10 will make 1000000 tuples in
 * pgbench_accounts table.
 */
static int  scale = 1;
 
/*
 * fillfactor. for example, fillfactor = 90 will use only 90 percent
 * space during inserts and leave 10 percent free.
 */
static int  fillfactor = 100;
 
/*
 * use unlogged tables?
 */
static bool unlogged_tables = false;
 
/*
 * log sampling rate (1.0 = log everything, 0.0 = option not given)
 */
static double sample_rate = 0.0;
 
/*
 * When threads are throttled to a given rate limit, this is the target delay
 * to reach that rate in usec.  0 is the default and means no throttling.
 */
static double throttle_delay = 0;
 
/*
 * Transactions which take longer than this limit (in usec) are counted as
 * late, and reported as such, although they are completed anyway. When
 * throttling is enabled, execution time slots that are more than this late
 * are skipped altogether, and counted separately.
 */
static int64 latency_limit = 0;
 
/*
 * tablespace selection
 */
static char *tablespace = NULL;
static char *index_tablespace = NULL;
 
/*
 * Number of "pgbench_accounts" partitions.  0 is the default and means no
 * partitioning.
 */
static int  partitions = 0;
 
/* partitioning strategy for "pgbench_accounts" */
typedef enum
{
    PART_NONE,                  /* no partitioning */
    PART_RANGE,                 /* range partitioning */
    PART_HASH,                  /* hash partitioning */
} partition_method_t;
 
static partition_method_t partition_method = PART_NONE;
static const char *const PARTITION_METHOD[] = {"none", "range", "hash"};
 
/* random seed used to initialize base_random_sequence */
static int64 random_seed = -1;
 
/*
 * end of configurable parameters
 *********************************************************************/
 
#define nbranches   1           /* Makes little sense to change this.  Change
                                 * -s instead */
#define ntellers    10
#define naccounts   100000
 
/*
 * The scale factor at/beyond which 32bit integers are incapable of storing
 * 64bit values.
 *
 * Although the actual threshold is 21474, we use 20000 because it is easier to
 * document and remember, and isn't that far away from the real threshold.
 */
#define SCALE_32BIT_THRESHOLD 20000
 
static bool use_log;            /* log transaction latencies to a file */
static bool use_quiet;          /* quiet logging onto stderr */
static int  agg_interval;       /* log aggregates instead of individual
                                 * transactions */
static bool per_script_stats = false;   /* whether to collect stats per script */
static int  progress = 0;       /* thread progress report every this seconds */
static bool progress_timestamp = false; /* progress report with Unix time */
static int  nclients = 1;       /* number of clients */
static int  nthreads = 1;       /* number of threads */
static bool is_connect;         /* establish connection for each transaction */
static bool report_per_command = false; /* report per-command latencies,
                                         * retries after errors and failures
                                         * (errors without retrying) */
static int  main_pid;           /* main process id used in log filename */
 
/*
 * There are different types of restrictions for deciding that the current
 * transaction with a serialization/deadlock error can no longer be retried and
 * should be reported as failed:
 * - max_tries (--max-tries) can be used to limit the number of tries;
 * - latency_limit (-L) can be used to limit the total time of tries;
 * - duration (-T) can be used to limit the total benchmark time.
 *
 * They can be combined together, and you need to use at least one of them to
 * retry the transactions with serialization/deadlock errors. If none of them is
 * used, the default value of max_tries is 1 and such transactions will not be
 * retried.
 */
 
/*
 * We cannot retry a transaction after the serialization/deadlock error if its
 * number of tries reaches this maximum; if its value is zero, it is not used.
 */
static uint32 max_tries = 1;
 
static bool failures_detailed = false;  /* whether to group failures in
                                         * reports or logs by basic types */
 
static const char *pghost = NULL;
static const char *pgport = NULL;
static const char *username = NULL;
static const char *dbName = NULL;
static char *logfile_prefix = NULL;
static const char *progname;
 
#define WSEP '@'                /* weight separator */
 
static volatile sig_atomic_t timer_exceeded = false;    /* flag from signal
                                                         * handler */
 
/*
 * We don't want to allocate variables one by one; for efficiency, add a
 * constant margin each time it overflows.
 */
#define VARIABLES_ALLOC_MARGIN  8
 
/*
 * Variable definitions.
 *
 * If a variable only has a string value, "svalue" is that value, and value is
 * "not set".  If the value is known, "value" contains the value (in any
 * variant).
 *
 * In this case "svalue" contains the string equivalent of the value, if we've
 * had occasion to compute that, or NULL if we haven't.
 */
typedef struct
{
    char       *name;           /* variable's name */
    char       *svalue;         /* its value in string form, if known */
    PgBenchValue value;         /* actual variable's value */
} Variable;
 
/*
 * Data structure for client variables.
 */
typedef struct
{
    Variable   *vars;           /* array of variable definitions */
    int         nvars;          /* number of variables */
 
    /*
     * The maximum number of variables that we can currently store in 'vars'
     * without having to reallocate more space. We must always have max_vars
     * >= nvars.
     */
    int         max_vars;
 
    bool        vars_sorted;    /* are variables sorted by name? */
} Variables;
 
#define MAX_SCRIPTS     128     /* max number of SQL scripts allowed */
#define SHELL_COMMAND_SIZE  256 /* maximum size allowed for shell command */
 
/*
 * Simple data structure to keep stats about something.
 *
 * XXX probably the first value should be kept and used as an offset for
 * better numerical stability...
 */
typedef struct SimpleStats
{
    int64       count;          /* how many values were encountered */
    double      min;            /* the minimum seen */
    double      max;            /* the maximum seen */
    double      sum;            /* sum of values */
    double      sum2;           /* sum of squared values */
} SimpleStats;
 
/*
 * The instr_time type is expensive when dealing with time arithmetic.  Define
 * a type to hold microseconds instead.  Type int64 is good enough for about
 * 584500 years.
 */
typedef int64 pg_time_usec_t;
 
/*
 * Data structure to hold various statistics: per-thread and per-script stats
 * are maintained and merged together.
 */
typedef struct StatsData
{
    pg_time_usec_t start_time;  /* interval start time, for aggregates */
 
    /*----------
     * Transactions are counted depending on their execution and outcome.
     * First a transaction may have started or not: skipped transactions occur
     * under --rate and --latency-limit when the client is too late to execute
     * them. Secondly, a started transaction may ultimately succeed or fail,
     * possibly after some retries when --max-tries is not one. Thus
     *
     * the number of all transactions =
     *   'skipped' (it was too late to execute them) +
     *   'cnt' (the number of successful transactions) +
     *   'failed' (the number of failed transactions).
     *
     * A successful transaction can have several unsuccessful tries before a
     * successful run. Thus
     *
     * 'cnt' (the number of successful transactions) =
     *   successfully retried transactions (they got a serialization or a
     *                                      deadlock error(s), but were
     *                                      successfully retried from the very
     *                                      beginning) +
     *   directly successful transactions (they were successfully completed on
     *                                     the first try).
     *
     * A failed transaction is defined as unsuccessfully retried transactions.
     * It can be one of two types:
     *
     * failed (the number of failed transactions) =
     *   'serialization_failures' (they got a serialization error and were not
     *                             successfully retried) +
     *   'deadlock_failures' (they got a deadlock error and were not
     *                        successfully retried).
     *
     * If the transaction was retried after a serialization or a deadlock
     * error this does not guarantee that this retry was successful. Thus
     *
     * 'retries' (number of retries) =
     *   number of retries in all retried transactions =
     *   number of retries in (successfully retried transactions +
     *                         failed transactions);
     *
     * 'retried' (number of all retried transactions) =
     *   successfully retried transactions +
     *   failed transactions.
     *----------
     */
    int64       cnt;            /* number of successful transactions, not
                                 * including 'skipped' */
    int64       skipped;        /* number of transactions skipped under --rate
                                 * and --latency-limit */
    int64       retries;        /* number of retries after a serialization or
                                 * a deadlock error in all the transactions */
    int64       retried;        /* number of all transactions that were
                                 * retried after a serialization or a deadlock
                                 * error (perhaps the last try was
                                 * unsuccessful) */
    int64       serialization_failures; /* number of transactions that were
                                         * not successfully retried after a
                                         * serialization error */
    int64       deadlock_failures;  /* number of transactions that were not
                                     * successfully retried after a deadlock
                                     * error */
    SimpleStats latency;
    SimpleStats lag;
} StatsData;
 
/*
 * For displaying Unix epoch timestamps, as some time functions may have
 * another reference.
 */
static pg_time_usec_t epoch_shift;
 
/*
 * Error status for errors during script execution.
 */
typedef enum EStatus
{
    ESTATUS_NO_ERROR = 0,
    ESTATUS_META_COMMAND_ERROR,
 
    /* SQL errors */
    ESTATUS_SERIALIZATION_ERROR,
    ESTATUS_DEADLOCK_ERROR,
    ESTATUS_OTHER_SQL_ERROR,
} EStatus;
 
/*
 * Transaction status at the end of a command.
 */
typedef enum TStatus
{
    TSTATUS_IDLE,
    TSTATUS_IN_BLOCK,
    TSTATUS_CONN_ERROR,
    TSTATUS_OTHER_ERROR,
} TStatus;
 
/* Various random sequences are initialized from this one. */
static pg_prng_state base_random_sequence;
 
/* Synchronization barrier for start and connection */
static THREAD_BARRIER_T barrier;
 
/*
 * Connection state machine states.
 */
typedef enum
{
    /*
     * The client must first choose a script to execute.  Once chosen, it can
     * either be throttled (state CSTATE_PREPARE_THROTTLE under --rate), start
     * right away (state CSTATE_START_TX) or not start at all if the timer was
     * exceeded (state CSTATE_FINISHED).
     */
    CSTATE_CHOOSE_SCRIPT,
 
    /*
     * CSTATE_START_TX performs start-of-transaction processing.  Establishes
     * a new connection for the transaction in --connect mode, records the
     * transaction start time, and proceed to the first command.
     *
     * Note: once a script is started, it will either error or run till its
     * end, where it may be interrupted. It is not interrupted while running,
     * so pgbench --time is to be understood as tx are allowed to start in
     * that time, and will finish when their work is completed.
     */
    CSTATE_START_TX,
 
    /*
     * In CSTATE_PREPARE_THROTTLE state, we calculate when to begin the next
     * transaction, and advance to CSTATE_THROTTLE.  CSTATE_THROTTLE state
     * sleeps until that moment, then advances to CSTATE_START_TX, or
     * CSTATE_FINISHED if the next transaction would start beyond the end of
     * the run.
     */
    CSTATE_PREPARE_THROTTLE,
    CSTATE_THROTTLE,
 
    /*
     * We loop through these states, to process each command in the script:
     *
     * CSTATE_START_COMMAND starts the execution of a command.  On a SQL
     * command, the command is sent to the server, and we move to
     * CSTATE_WAIT_RESULT state unless in pipeline mode. On a \sleep
     * meta-command, the timer is set, and we enter the CSTATE_SLEEP state to
     * wait for it to expire. Other meta-commands are executed immediately. If
     * the command about to start is actually beyond the end of the script,
     * advance to CSTATE_END_TX.
     *
     * CSTATE_WAIT_RESULT waits until we get a result set back from the server
     * for the current command.
     *
     * CSTATE_SLEEP waits until the end of \sleep.
     *
     * CSTATE_END_COMMAND records the end-of-command timestamp, increments the
     * command counter, and loops back to CSTATE_START_COMMAND state.
     *
     * CSTATE_SKIP_COMMAND is used by conditional branches which are not
     * executed. It quickly skip commands that do not need any evaluation.
     * This state can move forward several commands, till there is something
     * to do or the end of the script.
     */
    CSTATE_START_COMMAND,
    CSTATE_WAIT_RESULT,
    CSTATE_SLEEP,
    CSTATE_END_COMMAND,
    CSTATE_SKIP_COMMAND,
 
    /*
     * States for failed commands.
     *
     * If the SQL/meta command fails, in CSTATE_ERROR clean up after an error:
     * (1) clear the conditional stack; (2) if we have an unterminated
     * (possibly failed) transaction block, send the rollback command to the
     * server and wait for the result in CSTATE_WAIT_ROLLBACK_RESULT.  If
     * something goes wrong with rolling back, go to CSTATE_ABORTED.
     *
     * But if everything is ok we are ready for future transactions: if this
     * is a serialization or deadlock error and we can re-execute the
     * transaction from the very beginning, go to CSTATE_RETRY; otherwise go
     * to CSTATE_FAILURE.
     *
     * In CSTATE_RETRY report an error, set the same parameters for the
     * transaction execution as in the previous tries and process the first
     * transaction command in CSTATE_START_COMMAND.
     *
     * In CSTATE_FAILURE report a failure, set the parameters for the
     * transaction execution as they were before the first run of this
     * transaction (except for a random state) and go to CSTATE_END_TX to
     * complete this transaction.
     */
    CSTATE_ERROR,
    CSTATE_WAIT_ROLLBACK_RESULT,
    CSTATE_RETRY,
    CSTATE_FAILURE,
 
    /*
     * CSTATE_END_TX performs end-of-transaction processing.  It calculates
     * latency, and logs the transaction.  In --connect mode, it closes the
     * current connection.
     *
     * Then either starts over in CSTATE_CHOOSE_SCRIPT, or enters
     * CSTATE_FINISHED if we have no more work to do.
     */
    CSTATE_END_TX,
 
    /*
     * Final states.  CSTATE_ABORTED means that the script execution was
     * aborted because a command failed, CSTATE_FINISHED means success.
     */
    CSTATE_ABORTED,
    CSTATE_FINISHED,
} ConnectionStateEnum;
 
/*
 * Connection state.
 */
typedef struct
{
    PGconn     *con;            /* connection handle to DB */
    int         id;             /* client No. */
    ConnectionStateEnum state;  /* state machine's current state. */
    ConditionalStack cstack;    /* enclosing conditionals state */
 
    /*
     * Separate randomness for each client. This is used for random functions
     * PGBENCH_RANDOM_* during the execution of the script.
     */
    pg_prng_state cs_func_rs;
 
    int         use_file;       /* index in sql_script for this client */
    int         command;        /* command number in script */
    int         num_syncs;      /* number of ongoing sync commands */
 
    /* client variables */
    Variables   variables;
 
    /* various times about current transaction in microseconds */
    pg_time_usec_t txn_scheduled;   /* scheduled start time of transaction */
    pg_time_usec_t sleep_until; /* scheduled start time of next cmd */
    pg_time_usec_t txn_begin;   /* used for measuring schedule lag times */
    pg_time_usec_t stmt_begin;  /* used for measuring statement latencies */
 
    /* whether client prepared each command of each script */
    bool      **prepared;
 
    /*
     * For processing failures and repeating transactions with serialization
     * or deadlock errors:
     */
    EStatus     estatus;        /* the error status of the current transaction
                                 * execution; this is ESTATUS_NO_ERROR if
                                 * there were no errors */
    pg_prng_state random_state; /* random state */
    uint32      tries;          /* how many times have we already tried the
                                 * current transaction? */
 
    /* per client collected stats */
    int64       cnt;            /* client transaction count, for -t; skipped
                                 * and failed transactions are also counted
                                 * here */
} CState;
 
/*
 * Thread state
 */
typedef struct
{
    int         tid;            /* thread id */
    THREAD_T    thread;         /* thread handle */
    CState     *state;          /* array of CState */
    int         nstate;         /* length of state[] */
 
    /*
     * Separate randomness for each thread. Each thread option uses its own
     * random state to make all of them independent of each other and
     * therefore deterministic at the thread level.
     */
    pg_prng_state ts_choose_rs; /* random state for selecting a script */
    pg_prng_state ts_throttle_rs;   /* random state for transaction throttling */
    pg_prng_state ts_sample_rs; /* random state for log sampling */
 
    int64       throttle_trigger;   /* previous/next throttling (us) */
    FILE       *logfile;        /* where to log, or NULL */
 
    /* per thread collected stats in microseconds */
    pg_time_usec_t create_time; /* thread creation time */
    pg_time_usec_t started_time;    /* thread is running */
    pg_time_usec_t bench_start; /* thread is benchmarking */
    pg_time_usec_t conn_duration;   /* cumulated connection and disconnection
                                     * delays */
 
    StatsData   stats;
    int64       latency_late;   /* count executed but late transactions */
} TState;
 
/*
 * queries read from files
 */
#define SQL_COMMAND     1
#define META_COMMAND    2
 
/*
 * max number of backslash command arguments or SQL variables,
 * including the command or SQL statement itself
 */
#define MAX_ARGS        256
 
typedef enum MetaCommand
{
    META_NONE,                  /* not a known meta-command */
    META_SET,                   /* \set */
    META_SETSHELL,              /* \setshell */
    META_SHELL,                 /* \shell */
    META_SLEEP,                 /* \sleep */
    META_GSET,                  /* \gset */
    META_ASET,                  /* \aset */
    META_IF,                    /* \if */
    META_ELIF,                  /* \elif */
    META_ELSE,                  /* \else */
    META_ENDIF,                 /* \endif */
    META_STARTPIPELINE,         /* \startpipeline */
    META_SYNCPIPELINE,          /* \syncpipeline */
    META_ENDPIPELINE,           /* \endpipeline */
} MetaCommand;
 
typedef enum QueryMode
{
    QUERY_SIMPLE,               /* simple query */
    QUERY_EXTENDED,             /* extended query */
    QUERY_PREPARED,             /* extended query with prepared statements */
    NUM_QUERYMODE
} QueryMode;
 
static QueryMode querymode = QUERY_SIMPLE;
static const char *const QUERYMODE[] = {"simple", "extended", "prepared"};
 
/*
 * struct Command represents one command in a script.
 *
 * lines        The raw, possibly multi-line command text.  Variable substitution
 *              not applied.
 * first_line   A short, single-line extract of 'lines', for error reporting.
 * type         SQL_COMMAND or META_COMMAND
 * meta         The type of meta-command, with META_NONE/GSET/ASET if command
 *              is SQL.
 * argc         Number of arguments of the command, 0 if not yet processed.
 * argv         Command arguments, the first of which is the command or SQL
 *              string itself.  For SQL commands, after post-processing
 *              argv[0] is the same as 'lines' with variables substituted.
 * prepname     The name that this command is prepared under, in prepare mode
 * varprefix    SQL commands terminated with \gset or \aset have this set
 *              to a non NULL value.  If nonempty, it's used to prefix the
 *              variable name that receives the value.
 * aset         do gset on all possible queries of a combined query (\;).
 * expr         Parsed expression, if needed.
 * stats        Time spent in this command.
 * retries      Number of retries after a serialization or deadlock error in the
 *              current command.
 * failures     Number of errors in the current command that were not retried.
 */
typedef struct Command
{
    PQExpBufferData lines;
    char       *first_line;
    int         type;
    MetaCommand meta;
    int         argc;
    char       *argv[MAX_ARGS];
    char       *prepname;
    char       *varprefix;
    PgBenchExpr *expr;
    SimpleStats stats;
    int64       retries;
    int64       failures;
} Command;
 
typedef struct ParsedScript
{
    const char *desc;           /* script descriptor (eg, file name) */
    int         weight;         /* selection weight */
    Command   **commands;       /* NULL-terminated array of Commands */
    StatsData   stats;          /* total time spent in script */
} ParsedScript;
 
static ParsedScript sql_script[MAX_SCRIPTS];    /* SQL script files */
static int  num_scripts;        /* number of scripts in sql_script[] */
static int64 total_weight = 0;
 
static bool verbose_errors = false; /* print verbose messages of all errors */
 
static bool exit_on_abort = false;  /* exit when any client is aborted */
 
/* Builtin test scripts */
typedef struct BuiltinScript
{
    const char *name;           /* very short name for -b ... */
    const char *desc;           /* short description */
    const char *script;         /* actual pgbench script */
} BuiltinScript;
 
static const BuiltinScript builtin_script[] =
{
    {
        "tpcb-like",
        "<builtin: TPC-B (sort of)>",
        "\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
        "\\set bid random(1, " CppAsString2(nbranches) " * :scale)\n"
        "\\set tid random(1, " CppAsString2(ntellers) " * :scale)\n"
        "\\set delta random(-5000, 5000)\n"
        "BEGIN;\n"
        "UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
        "SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
        "UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;\n"
        "UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;\n"
        "INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
        "END;\n"
    },
    {
        "simple-update",
        "<builtin: simple update>",
        "\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
        "\\set bid random(1, " CppAsString2(nbranches) " * :scale)\n"
        "\\set tid random(1, " CppAsString2(ntellers) " * :scale)\n"
        "\\set delta random(-5000, 5000)\n"
        "BEGIN;\n"
        "UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
        "SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
        "INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
        "END;\n"
    },
    {
        "select-only",
        "<builtin: select only>",
        "\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
        "SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
    }
};
 
 
/* Function prototypes */
static void setNullValue(PgBenchValue *pv);
static void setBoolValue(PgBenchValue *pv, bool bval);
static void setIntValue(PgBenchValue *pv, int64 ival);
static void setDoubleValue(PgBenchValue *pv, double dval);
static bool evaluateExpr(CState *st, PgBenchExpr *expr,
                         PgBenchValue *retval);
static ConnectionStateEnum executeMetaCommand(CState *st, pg_time_usec_t *now);
static void doLog(TState *thread, CState *st,
                  StatsData *agg, bool skipped, double latency, double lag);
static void processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
                             bool skipped, StatsData *agg);
static void addScript(const ParsedScript *script);
static THREAD_FUNC_RETURN_TYPE THREAD_FUNC_CC threadRun(void *arg);
static void finishCon(CState *st);
static void setalarm(int seconds);
static socket_set *alloc_socket_set(int count);
static void free_socket_set(socket_set *sa);
static void clear_socket_set(socket_set *sa);
static void add_socket_to_set(socket_set *sa, int fd, int idx);
static int  wait_on_socket_set(socket_set *sa, int64 usecs);
static bool socket_has_input(socket_set *sa, int fd, int idx);
 
/* callback used to build rows for COPY during data loading */
typedef void (*initRowMethod) (PQExpBufferData *sql, int64 curr);
 
/* callback functions for our flex lexer */
static const PsqlScanCallbacks pgbench_callbacks = {
    NULL,                       /* don't need get_variable functionality */
};
 
static inline pg_time_usec_t
pg_time_now(void)
{
    instr_time  now;
 
    INSTR_TIME_SET_CURRENT(now);
 
    return (pg_time_usec_t) INSTR_TIME_GET_MICROSEC(now);
}
 
static inline void
pg_time_now_lazy(pg_time_usec_t *now)
{
    if ((*now) == 0)
        (*now) = pg_time_now();
}
 
#define PG_TIME_GET_DOUBLE(t) (0.000001 * (t))
 
static void
usage(void)
{
    printf("%s is a benchmarking tool for PostgreSQL.\n\n"
           "Usage:\n"
           "  %s [OPTION]... [DBNAME]\n"
           "\nInitialization options:\n"
           "  -i, --initialize         invokes initialization mode\n"
           "  -I, --init-steps=[" ALL_INIT_STEPS "]+ (default \"" DEFAULT_INIT_STEPS "\")\n"
           "                           run selected initialization steps, in the specified order\n"
           "                           d: drop any existing pgbench tables\n"
           "                           t: create the tables used by the standard pgbench scenario\n"
           "                           g: generate data, client-side\n"
           "                           G: generate data, server-side\n"
           "                           v: invoke VACUUM on the standard tables\n"
           "                           p: create primary key indexes on the standard tables\n"
           "                           f: create foreign keys between the standard tables\n"
           "  -F, --fillfactor=NUM     set fill factor\n"
           "  -n, --no-vacuum          do not run VACUUM during initialization\n"
           "  -q, --quiet              quiet logging (one message each 5 seconds)\n"
           "  -s, --scale=NUM          scaling factor\n"
           "  --foreign-keys           create foreign key constraints between tables\n"
           "  --index-tablespace=TABLESPACE\n"
           "                           create indexes in the specified tablespace\n"
           "  --partition-method=(range|hash)\n"
           "                           partition pgbench_accounts with this method (default: range)\n"
           "  --partitions=NUM         partition pgbench_accounts into NUM parts (default: 0)\n"
           "  --tablespace=TABLESPACE  create tables in the specified tablespace\n"
           "  --unlogged-tables        create tables as unlogged tables\n"
           "\nOptions to select what to run:\n"
           "  -b, --builtin=NAME[@W]   add builtin script NAME weighted at W (default: 1)\n"
           "                           (use \"-b list\" to list available scripts)\n"
           "  -f, --file=FILENAME[@W]  add script FILENAME weighted at W (default: 1)\n"
           "  -N, --skip-some-updates  skip updates of pgbench_tellers and pgbench_branches\n"
           "                           (same as \"-b simple-update\")\n"
           "  -S, --select-only        perform SELECT-only transactions\n"
           "                           (same as \"-b select-only\")\n"
           "\nBenchmarking options:\n"
           "  -c, --client=NUM         number of concurrent database clients (default: 1)\n"
           "  -C, --connect            establish new connection for each transaction\n"
           "  -D, --define=VARNAME=VALUE\n"
           "                           define variable for use by custom script\n"
           "  -j, --jobs=NUM           number of threads (default: 1)\n"
           "  -l, --log                write transaction times to log file\n"
           "  -L, --latency-limit=NUM  count transactions lasting more than NUM ms as late\n"
           "  -M, --protocol=simple|extended|prepared\n"
           "                           protocol for submitting queries (default: simple)\n"
           "  -n, --no-vacuum          do not run VACUUM before tests\n"
           "  -P, --progress=NUM       show thread progress report every NUM seconds\n"
           "  -r, --report-per-command report latencies, failures, and retries per command\n"
           "  -R, --rate=NUM           target rate in transactions per second\n"
           "  -s, --scale=NUM          report this scale factor in output\n"
           "  -t, --transactions=NUM   number of transactions each client runs (default: 10)\n"
           "  -T, --time=NUM           duration of benchmark test in seconds\n"
           "  -v, --vacuum-all         vacuum all four standard tables before tests\n"
           "  --aggregate-interval=NUM aggregate data over NUM seconds\n"
           "  --exit-on-abort          exit when any client is aborted\n"
           "  --failures-detailed      report the failures grouped by basic types\n"
           "  --log-prefix=PREFIX      prefix for transaction time log file\n"
           "                           (default: \"pgbench_log\")\n"
           "  --max-tries=NUM          max number of tries to run transaction (default: 1)\n"
           "  --progress-timestamp     use Unix epoch timestamps for progress\n"
           "  --random-seed=SEED       set random seed (\"time\", \"rand\", integer)\n"
           "  --sampling-rate=NUM      fraction of transactions to log (e.g., 0.01 for 1%%)\n"
           "  --show-script=NAME       show builtin script code, then exit\n"
           "  --verbose-errors         print messages of all errors\n"
           "\nCommon options:\n"
           "  --debug                  print debugging output\n"
           "  -d, --dbname=DBNAME      database name to connect to\n"
           "  -h, --host=HOSTNAME      database server host or socket directory\n"
           "  -p, --port=PORT          database server port number\n"
           "  -U, --username=USERNAME  connect as specified database user\n"
           "  -V, --version            output version information, then exit\n"
           "  -?, --help               show this help, then exit\n"
           "\n"
           "Report bugs to <%s>.\n"
           "%s home page: <%s>\n",
           progname, progname, PACKAGE_BUGREPORT, PACKAGE_NAME, PACKAGE_URL);
}
 
/* return whether str matches "^\s*[-+]?[0-9]+$" */
static bool
is_an_int(const char *str)
{
    const char *ptr = str;
 
    /* skip leading spaces; cast is consistent with strtoint64 */
    while (*ptr && isspace((unsigned char) *ptr))
        ptr++;
 
    /* skip sign */
    if (*ptr == '+' || *ptr == '-')
        ptr++;
 
    /* at least one digit */
    if (*ptr && !isdigit((unsigned char) *ptr))
        return false;
 
    /* eat all digits */
    while (*ptr && isdigit((unsigned char) *ptr))
        ptr++;
 
    /* must have reached end of string */
    return *ptr == '\0';
}
 
 
/*
 * strtoint64 -- convert a string to 64-bit integer
 *
 * This function is a slightly modified version of pg_strtoint64() from
 * src/backend/utils/adt/numutils.c.
 *
 * The function returns whether the conversion worked, and if so
 * "*result" is set to the result.
 *
 * If not errorOK, an error message is also printed out on errors.
 */
bool
strtoint64(const char *str, bool errorOK, int64 *result)
{
    const char *ptr = str;
    int64       tmp = 0;
    bool        neg = false;
 
    /*
     * Do our own scan, rather than relying on sscanf which might be broken
     * for long long.
     *
     * As INT64_MIN can't be stored as a positive 64 bit integer, accumulate
     * value as a negative number.
     */
 
    /* skip leading spaces */
    while (*ptr && isspace((unsigned char) *ptr))
        ptr++;
 
    /* handle sign */
    if (*ptr == '-')
    {
        ptr++;
        neg = true;
    }
    else if (*ptr == '+')
        ptr++;
 
    /* require at least one digit */
    if (unlikely(!isdigit((unsigned char) *ptr)))
        goto invalid_syntax;
 
    /* process digits */
    while (*ptr && isdigit((unsigned char) *ptr))
    {
        int8        digit = (*ptr++ - '0');
 
        if (unlikely(pg_mul_s64_overflow(tmp, 10, &tmp)) ||
            unlikely(pg_sub_s64_overflow(tmp, digit, &tmp)))
            goto out_of_range;
    }
 
    /* allow trailing whitespace, but not other trailing chars */
    while (*ptr != '\0' && isspace((unsigned char) *ptr))
        ptr++;
 
    if (unlikely(*ptr != '\0'))
        goto invalid_syntax;
 
    if (!neg)
    {
        if (unlikely(tmp == PG_INT64_MIN))
            goto out_of_range;
        tmp = -tmp;
    }
 
    *result = tmp;
    return true;
 
out_of_range:
    if (!errorOK)
        pg_log_error("value \"%s\" is out of range for type bigint", str);
    return false;
 
invalid_syntax:
    if (!errorOK)
        pg_log_error("invalid input syntax for type bigint: \"%s\"", str);
    return false;
}
 
/* convert string to double, detecting overflows/underflows */
bool
strtodouble(const char *str, bool errorOK, double *dv)
{
    char       *end;
 
    errno = 0;
    *dv = strtod(str, &end);
 
    if (unlikely(errno != 0))
    {
        if (!errorOK)
            pg_log_error("value \"%s\" is out of range for type double", str);
        return false;
    }
 
    if (unlikely(end == str || *end != '\0'))
    {
        if (!errorOK)
            pg_log_error("invalid input syntax for type double: \"%s\"", str);
        return false;
    }
    return true;
}
 
/*
 * Initialize a prng state struct.
 *
 * We derive the seed from base_random_sequence, which must be set up already.
 */
static void
initRandomState(pg_prng_state *state)
{
    pg_prng_seed(state, pg_prng_uint64(&base_random_sequence));
}
 
 
/*
 * random number generator: uniform distribution from min to max inclusive.
 *
 * Although the limits are expressed as int64, you can't generate the full
 * int64 range in one call, because the difference of the limits mustn't
 * overflow int64.  This is not checked.
 */
static int64
getrand(pg_prng_state *state, int64 min, int64 max)
{
    return min + (int64) pg_prng_uint64_range(state, 0, max - min);
}
 
/*
 * random number generator: exponential distribution from min to max inclusive.
 * the parameter is so that the density of probability for the last cut-off max
 * value is exp(-parameter).
 */
static int64
getExponentialRand(pg_prng_state *state, int64 min, int64 max,
                   double parameter)
{
    double      cut,
                uniform,
                rand;
 
    /* abort if wrong parameter, but must really be checked beforehand */
    Assert(parameter > 0.0);
    cut = exp(-parameter);
    /* pg_prng_double value in [0, 1), uniform in (0, 1] */
    uniform = 1.0 - pg_prng_double(state);
 
    /*
     * inner expression in (cut, 1] (if parameter > 0), rand in [0, 1)
     */
    Assert((1.0 - cut) != 0.0);
    rand = -log(cut + (1.0 - cut) * uniform) / parameter;
    /* return int64 random number within between min and max */
    return min + (int64) ((max - min + 1) * rand);
}
 
/* random number generator: gaussian distribution from min to max inclusive */
static int64
getGaussianRand(pg_prng_state *state, int64 min, int64 max,
                double parameter)
{
    double      stdev;
    double      rand;
 
    /* abort if parameter is too low, but must really be checked beforehand */
    Assert(parameter >= MIN_GAUSSIAN_PARAM);
 
    /*
     * Get normally-distributed random number in the range -parameter <= stdev
     * < parameter.
     *
     * This loop is executed until the number is in the expected range.
     *
     * As the minimum parameter is 2.0, the probability of looping is low:
     * sqrt(-2 ln(r)) <= 2 => r >= e^{-2} ~ 0.135, then when taking the
     * average sinus multiplier as 2/pi, we have a 8.6% looping probability in
     * the worst case. For a parameter value of 5.0, the looping probability
     * is about e^{-5} * 2 / pi ~ 0.43%.
     */
    do
    {
        stdev = pg_prng_double_normal(state);
    }
    while (stdev < -parameter || stdev >= parameter);
 
    /* stdev is in [-parameter, parameter), normalization to [0,1) */
    rand = (stdev + parameter) / (parameter * 2.0);
 
    /* return int64 random number within between min and max */
    return min + (int64) ((max - min + 1) * rand);
}
 
/*
 * random number generator: generate a value, such that the series of values
 * will approximate a Poisson distribution centered on the given value.
 *
 * Individual results are rounded to integers, though the center value need
 * not be one.
 */
static int64
getPoissonRand(pg_prng_state *state, double center)
{
    /*
     * Use inverse transform sampling to generate a value > 0, such that the
     * expected (i.e. average) value is the given argument.
     */
    double      uniform;
 
    /* pg_prng_double value in [0, 1), uniform in (0, 1] */
    uniform = 1.0 - pg_prng_double(state);
 
    return (int64) (-log(uniform) * center + 0.5);
}
 
/*
 * Computing zipfian using rejection method, based on
 * "Non-Uniform Random Variate Generation",
 * Luc Devroye, p. 550-551, Springer 1986.
 *
 * This works for s > 1.0, but may perform badly for s very close to 1.0.
 */
static int64
computeIterativeZipfian(pg_prng_state *state, int64 n, double s)
{
    double      b = pow(2.0, s - 1.0);
    double      x,
                t,
                u,
                v;
 
    /* Ensure n is sane */
    if (n <= 1)
        return 1;
 
    while (true)
    {
        /* random variates */
        u = pg_prng_double(state);
        v = pg_prng_double(state);
 
        x = floor(pow(u, -1.0 / (s - 1.0)));
 
        t = pow(1.0 + 1.0 / x, s - 1.0);
        /* reject if too large or out of bound */
        if (v * x * (t - 1.0) / (b - 1.0) <= t / b && x <= n)
            break;
    }
    return (int64) x;
}
 
/* random number generator: zipfian distribution from min to max inclusive */
static int64
getZipfianRand(pg_prng_state *state, int64 min, int64 max, double s)
{
    int64       n = max - min + 1;
 
    /* abort if parameter is invalid */
    Assert(MIN_ZIPFIAN_PARAM <= s && s <= MAX_ZIPFIAN_PARAM);
 
    return min - 1 + computeIterativeZipfian(state, n, s);
}
 
/*
 * FNV-1a hash function
 */
static int64
getHashFnv1a(int64 val, uint64 seed)
{
    int64       result;
    int         i;
 
    result = FNV_OFFSET_BASIS ^ seed;
    for (i = 0; i < 8; ++i)
    {
        int32       octet = val & 0xff;
 
        val = val >> 8;
        result = result ^ octet;
        result = result * FNV_PRIME;
    }
 
    return result;
}
 
/*
 * Murmur2 hash function
 *
 * Based on original work of Austin Appleby
 * https://github.com/aappleby/smhasher/blob/master/src/MurmurHash2.cpp
 */
static int64
getHashMurmur2(int64 val, uint64 seed)
{
    uint64      result = seed ^ MM2_MUL_TIMES_8;    /* sizeof(int64) */
    uint64      k = (uint64) val;
 
    k *= MM2_MUL;
    k ^= k >> MM2_ROT;
    k *= MM2_MUL;
 
    result ^= k;
    result *= MM2_MUL;
 
    result ^= result >> MM2_ROT;
    result *= MM2_MUL;
    result ^= result >> MM2_ROT;
 
    return (int64) result;
}
 
/*
 * Pseudorandom permutation function
 *
 * For small sizes, this generates each of the (size!) possible permutations
 * of integers in the range [0, size) with roughly equal probability.  Once
 * the size is larger than 20, the number of possible permutations exceeds the
 * number of distinct states of the internal pseudorandom number generator,
 * and so not all possible permutations can be generated, but the permutations
 * chosen should continue to give the appearance of being random.
 *
 * THIS FUNCTION IS NOT CRYPTOGRAPHICALLY SECURE.
 * DO NOT USE FOR SUCH PURPOSE.
 */
static int64
permute(const int64 val, const int64 isize, const int64 seed)
{
    /* using a high-end PRNG is probably overkill */
    pg_prng_state state;
    uint64      size;
    uint64      v;
    int         masklen;
    uint64      mask;
    int         i;
 
    if (isize < 2)
        return 0;               /* nothing to permute */
 
    /* Initialize prng state using the seed */
    pg_prng_seed(&state, (uint64) seed);
 
    /* Computations are performed on unsigned values */
    size = (uint64) isize;
    v = (uint64) val % size;
 
    /* Mask to work modulo largest power of 2 less than or equal to size */
    masklen = pg_leftmost_one_pos64(size);
    mask = (((uint64) 1) << masklen) - 1;
 
    /*
     * Permute the input value by applying several rounds of pseudorandom
     * bijective transformations.  The intention here is to distribute each
     * input uniformly randomly across the range, and separate adjacent inputs
     * approximately uniformly randomly from each other, leading to a fairly
     * random overall choice of permutation.
     *
     * To separate adjacent inputs, we multiply by a random number modulo
     * (mask + 1), which is a power of 2.  For this to be a bijection, the
     * multiplier must be odd.  Since this is known to lead to less randomness
     * in the lower bits, we also apply a rotation that shifts the topmost bit
     * into the least significant bit.  In the special cases where size <= 3,
     * mask = 1 and each of these operations is actually a no-op, so we also
     * XOR the value with a different random number to inject additional
     * randomness.  Since the size is generally not a power of 2, we apply
     * this bijection on overlapping upper and lower halves of the input.
     *
     * To distribute the inputs uniformly across the range, we then also apply
     * a random offset modulo the full range.
     *
     * Taken together, these operations resemble a modified linear
     * congruential generator, as is commonly used in pseudorandom number
     * generators.  The number of rounds is fairly arbitrary, but six has been
     * found empirically to give a fairly good tradeoff between performance
     * and uniform randomness.  For small sizes it selects each of the (size!)
     * possible permutations with roughly equal probability.  For larger
     * sizes, not all permutations can be generated, but the intended random
     * spread is still produced.
     */
    for (i = 0; i < 6; i++)
    {
        uint64      m,
                    r,
                    t;
 
        /* Random multiply (by an odd number), XOR and rotate of lower half */
        m = (pg_prng_uint64(&state) & mask) | 1;
        r = pg_prng_uint64(&state) & mask;
        if (v <= mask)
        {
            v = ((v * m) ^ r) & mask;
            v = ((v << 1) & mask) | (v >> (masklen - 1));
        }
 
        /* Random multiply (by an odd number), XOR and rotate of upper half */
        m = (pg_prng_uint64(&state) & mask) | 1;
        r = pg_prng_uint64(&state) & mask;
        t = size - 1 - v;
        if (t <= mask)
        {
            t = ((t * m) ^ r) & mask;
            t = ((t << 1) & mask) | (t >> (masklen - 1));
            v = size - 1 - t;
        }
 
        /* Random offset */
        r = pg_prng_uint64_range(&state, 0, size - 1);
        v = (v + r) % size;
    }
 
    return (int64) v;
}
 
/*
 * Initialize the given SimpleStats struct to all zeroes
 */
static void
initSimpleStats(SimpleStats *ss)
{
    memset(ss, 0, sizeof(SimpleStats));
}
 
/*
 * Accumulate one value into a SimpleStats struct.
 */
static void
addToSimpleStats(SimpleStats *ss, double val)
{
    if (ss->count == 0 || val < ss->min)
        ss->min = val;
    if (ss->count == 0 || val > ss->max)
        ss->max = val;
    ss->count++;
    ss->sum += val;
    ss->sum2 += val * val;
}
 
/*
 * Merge two SimpleStats objects
 */
static void
mergeSimpleStats(SimpleStats *acc, SimpleStats *ss)
{
    if (acc->count == 0 || ss->min < acc->min)
        acc->min = ss->min;
    if (acc->count == 0 || ss->max > acc->max)
        acc->max = ss->max;
    acc->count += ss->count;
    acc->sum += ss->sum;
    acc->sum2 += ss->sum2;
}
 
/*
 * Initialize a StatsData struct to mostly zeroes, with its start time set to
 * the given value.
 */
static void
initStats(StatsData *sd, pg_time_usec_t start)
{
    sd->start_time = start;
    sd->cnt = 0;
    sd->skipped = 0;
    sd->retries = 0;
    sd->retried = 0;
    sd->serialization_failures = 0;
    sd->deadlock_failures = 0;
    initSimpleStats(&sd->latency);
    initSimpleStats(&sd->lag);
}
 
/*
 * Accumulate one additional item into the given stats object.
 */
static void
accumStats(StatsData *stats, bool skipped, double lat, double lag,
           EStatus estatus, int64 tries)
{
    /* Record the skipped transaction */
    if (skipped)
    {
        /* no latency to record on skipped transactions */
        stats->skipped++;
        return;
    }
 
    /*
     * Record the number of retries regardless of whether the transaction was
     * successful or failed.
     */
    if (tries > 1)
    {
        stats->retries += (tries - 1);
        stats->retried++;
    }
 
    switch (estatus)
    {
            /* Record the successful transaction */
        case ESTATUS_NO_ERROR:
            stats->cnt++;
 
            addToSimpleStats(&stats->latency, lat);
 
            /* and possibly the same for schedule lag */
            if (throttle_delay)
                addToSimpleStats(&stats->lag, lag);
            break;
 
            /* Record the failed transaction */
        case ESTATUS_SERIALIZATION_ERROR:
            stats->serialization_failures++;
            break;
        case ESTATUS_DEADLOCK_ERROR:
            stats->deadlock_failures++;
            break;
        default:
            /* internal error which should never occur */
            pg_fatal("unexpected error status: %d", estatus);
    }
}
 
/* call PQexec() and exit() on failure */
static void
executeStatement(PGconn *con, const char *sql)
{
    PGresult   *res;
 
    res = PQexec(con, sql);
    if (PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        pg_log_error("query failed: %s", PQerrorMessage(con));
        pg_log_error_detail("Query was: %s", sql);
        exit(1);
    }
    PQclear(res);
}
 
/* call PQexec() and complain, but without exiting, on failure */
static void
tryExecuteStatement(PGconn *con, const char *sql)
{
    PGresult   *res;
 
    res = PQexec(con, sql);
    if (PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        pg_log_error("%s", PQerrorMessage(con));
        pg_log_error_detail("(ignoring this error and continuing anyway)");
    }
    PQclear(res);
}
 
/* set up a connection to the backend */
static PGconn *
doConnect(void)
{
    PGconn     *conn;
    bool        new_pass;
    static char *password = NULL;
 
    /*
     * Start the connection.  Loop until we have a password if requested by
     * backend.
     */
    do
    {
#define PARAMS_ARRAY_SIZE   7
 
        const char *keywords[PARAMS_ARRAY_SIZE];
        const char *values[PARAMS_ARRAY_SIZE];
 
        keywords[0] = "host";
        values[0] = pghost;
        keywords[1] = "port";
        values[1] = pgport;
        keywords[2] = "user";
        values[2] = username;
        keywords[3] = "password";
        values[3] = password;
        keywords[4] = "dbname";
        values[4] = dbName;
        keywords[5] = "fallback_application_name";
        values[5] = progname;
        keywords[6] = NULL;
        values[6] = NULL;
 
        new_pass = false;
 
        conn = PQconnectdbParams(keywords, values, true);
 
        if (!conn)
        {
            pg_log_error("connection to database \"%s\" failed", dbName);
            return NULL;
        }
 
        if (PQstatus(conn) == CONNECTION_BAD &&
            PQconnectionNeedsPassword(conn) &&
            !password)
        {
            PQfinish(conn);
            password = simple_prompt("Password: ", false);
            new_pass = true;
        }
    } while (new_pass);
 
    /* check to see that the backend connection was successfully made */
    if (PQstatus(conn) == CONNECTION_BAD)
    {
        pg_log_error("%s", PQerrorMessage(conn));
        PQfinish(conn);
        return NULL;
    }
 
    return conn;
}
 
/* qsort comparator for Variable array */
static int
compareVariableNames(const void *v1, const void *v2)
{
    return strcmp(((const Variable *) v1)->name,
                  ((const Variable *) v2)->name);
}
 
/* Locate a variable by name; returns NULL if unknown */
static Variable *
lookupVariable(Variables *variables, char *name)
{
    Variable    key;
 
    /* On some versions of Solaris, bsearch of zero items dumps core */
    if (variables->nvars <= 0)
        return NULL;
 
    /* Sort if we have to */
    if (!variables->vars_sorted)
    {
        qsort(variables->vars, variables->nvars, sizeof(Variable),
              compareVariableNames);
        variables->vars_sorted = true;
    }
 
    /* Now we can search */
    key.name = name;
    return (Variable *) bsearch(&key,
                                variables->vars,
                                variables->nvars,
                                sizeof(Variable),
                                compareVariableNames);
}
 
/* Get the value of a variable, in string form; returns NULL if unknown */
static char *
getVariable(Variables *variables, char *name)
{
    Variable   *var;
    char        stringform[64];
 
    var = lookupVariable(variables, name);
    if (var == NULL)
        return NULL;            /* not found */
 
    if (var->svalue)
        return var->svalue;     /* we have it in string form */
 
    /* We need to produce a string equivalent of the value */
    Assert(var->value.type != PGBT_NO_VALUE);
    if (var->value.type == PGBT_NULL)
        snprintf(stringform, sizeof(stringform), "NULL");
    else if (var->value.type == PGBT_BOOLEAN)
        snprintf(stringform, sizeof(stringform),
                 "%s", var->value.u.bval ? "true" : "false");
    else if (var->value.type == PGBT_INT)
        snprintf(stringform, sizeof(stringform),
                 INT64_FORMAT, var->value.u.ival);
    else if (var->value.type == PGBT_DOUBLE)
        snprintf(stringform, sizeof(stringform),
                 "%.*g", DBL_DIG, var->value.u.dval);
    else                        /* internal error, unexpected type */
        Assert(0);
    var->svalue = pg_strdup(stringform);
    return var->svalue;
}
 
/* Try to convert variable to a value; return false on failure */
static bool
makeVariableValue(Variable *var)
{
    size_t      slen;
 
    if (var->value.type != PGBT_NO_VALUE)
        return true;            /* no work */
 
    slen = strlen(var->svalue);
 
    if (slen == 0)
        /* what should it do on ""? */
        return false;
 
    if (pg_strcasecmp(var->svalue, "null") == 0)
    {
        setNullValue(&var->value);
    }
 
    /*
     * accept prefixes such as y, ye, n, no... but not for "o". 0/1 are
     * recognized later as an int, which is converted to bool if needed.
     */
    else if (pg_strncasecmp(var->svalue, "true", slen) == 0 ||
             pg_strncasecmp(var->svalue, "yes", slen) == 0 ||
             pg_strcasecmp(var->svalue, "on") == 0)
    {
        setBoolValue(&var->value, true);
    }
    else if (pg_strncasecmp(var->svalue, "false", slen) == 0 ||
             pg_strncasecmp(var->svalue, "no", slen) == 0 ||
             pg_strcasecmp(var->svalue, "off") == 0 ||
             pg_strcasecmp(var->svalue, "of") == 0)
    {
        setBoolValue(&var->value, false);
    }
    else if (is_an_int(var->svalue))
    {
        /* if it looks like an int, it must be an int without overflow */
        int64       iv;
 
        if (!strtoint64(var->svalue, false, &iv))
            return false;
 
        setIntValue(&var->value, iv);
    }
    else                        /* type should be double */
    {
        double      dv;
 
        if (!strtodouble(var->svalue, true, &dv))
        {
            pg_log_error("malformed variable \"%s\" value: \"%s\"",
                         var->name, var->svalue);
            return false;
        }
        setDoubleValue(&var->value, dv);
    }
    return true;
}
 
/*
 * Check whether a variable's name is allowed.
 *
 * We allow any non-ASCII character, as well as ASCII letters, digits, and
 * underscore.
 *
 * Keep this in sync with the definitions of variable name characters in
 * "src/fe_utils/psqlscan.l", "src/bin/psql/psqlscanslash.l" and
 * "src/bin/pgbench/exprscan.l".  Also see parseVariable(), below.
 *
 * Note: this static function is copied from "src/bin/psql/variables.c"
 * but changed to disallow variable names starting with a digit.
 */
static bool
valid_variable_name(const char *name)
{
    const unsigned char *ptr = (const unsigned char *) name;
 
    /* Mustn't be zero-length */
    if (*ptr == '\0')
        return false;
 
    /* must not start with [0-9] */
    if (IS_HIGHBIT_SET(*ptr) ||
        strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
               "_", *ptr) != NULL)
        ptr++;
    else
        return false;
 
    /* remaining characters can include [0-9] */
    while (*ptr)
    {
        if (IS_HIGHBIT_SET(*ptr) ||
            strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                   "_0123456789", *ptr) != NULL)
            ptr++;
        else
            return false;
    }
 
    return true;
}
 
/*
 * Make sure there is enough space for 'needed' more variable in the variables
 * array.
 */
static void
enlargeVariables(Variables *variables, int needed)
{
    /* total number of variables required now */
    needed += variables->nvars;
 
    if (variables->max_vars < needed)
    {
        variables->max_vars = needed + VARIABLES_ALLOC_MARGIN;
        variables->vars = (Variable *)
            pg_realloc(variables->vars, variables->max_vars * sizeof(Variable));
    }
}
 
/*
 * Lookup a variable by name, creating it if need be.
 * Caller is expected to assign a value to the variable.
 * Returns NULL on failure (bad name).
 */
static Variable *
lookupCreateVariable(Variables *variables, const char *context, char *name)
{
    Variable   *var;
 
    var = lookupVariable(variables, name);
    if (var == NULL)
    {
        /*
         * Check for the name only when declaring a new variable to avoid
         * overhead.
         */
        if (!valid_variable_name(name))
        {
            pg_log_error("%s: invalid variable name: \"%s\"", context, name);
            return NULL;
        }
 
        /* Create variable at the end of the array */
        enlargeVariables(variables, 1);
 
        var = &(variables->vars[variables->nvars]);
 
        var->name = pg_strdup(name);
        var->svalue = NULL;
        /* caller is expected to initialize remaining fields */
 
        variables->nvars++;
        /* we don't re-sort the array till we have to */
        variables->vars_sorted = false;
    }
 
    return var;
}
 
/* Assign a string value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariable(Variables *variables, const char *context, char *name,
            const char *value)
{
    Variable   *var;
    char       *val;
 
    var = lookupCreateVariable(variables, context, name);
    if (!var)
        return false;
 
    /* dup then free, in case value is pointing at this variable */
    val = pg_strdup(value);
 
    free(var->svalue);
    var->svalue = val;
    var->value.type = PGBT_NO_VALUE;
 
    return true;
}
 
/* Assign a value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariableValue(Variables *variables, const char *context, char *name,
                 const PgBenchValue *value)
{
    Variable   *var;
 
    var = lookupCreateVariable(variables, context, name);
    if (!var)
        return false;
 
    free(var->svalue);
    var->svalue = NULL;
    var->value = *value;
 
    return true;
}
 
/* Assign an integer value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariableInt(Variables *variables, const char *context, char *name,
               int64 value)
{
    PgBenchValue val;
 
    setIntValue(&val, value);
    return putVariableValue(variables, context, name, &val);
}
 
/*
 * Parse a possible variable reference (:varname).
 *
 * "sql" points at a colon.  If what follows it looks like a valid
 * variable name, return a malloc'd string containing the variable name,
 * and set *eaten to the number of characters consumed (including the colon).
 * Otherwise, return NULL.
 */
static char *
parseVariable(const char *sql, int *eaten)
{
    int         i = 1;          /* starting at 1 skips the colon */
    char       *name;
 
    /* keep this logic in sync with valid_variable_name() */
    if (IS_HIGHBIT_SET(sql[i]) ||
        strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
               "_", sql[i]) != NULL)
        i++;
    else
        return NULL;
 
    while (IS_HIGHBIT_SET(sql[i]) ||
           strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                  "_0123456789", sql[i]) != NULL)
        i++;
 
    name = pg_malloc(i);
    memcpy(name, &sql[1], i - 1);
    name[i - 1] = '\0';
 
    *eaten = i;
    return name;
}
 
static char *
replaceVariable(char **sql, char *param, int len, char *value)
{
    int         valueln = strlen(value);
 
    if (valueln > len)
    {
        size_t      offset = param - *sql;
 
        *sql = pg_realloc(*sql, strlen(*sql) - len + valueln + 1);
        param = *sql + offset;
    }
 
    if (valueln != len)
        memmove(param + valueln, param + len, strlen(param + len) + 1);
    memcpy(param, value, valueln);
 
    return param + valueln;
}
 
static char *
assignVariables(Variables *variables, char *sql)
{
    char       *p,
               *name,
               *val;
 
    p = sql;
    while ((p = strchr(p, ':')) != NULL)
    {
        int         eaten;
 
        name = parseVariable(p, &eaten);
        if (name == NULL)
        {
            while (*p == ':')
            {
                p++;
            }
            continue;
        }
 
        val = getVariable(variables, name);
        free(name);
        if (val == NULL)
        {
            p++;
            continue;
        }
 
        p = replaceVariable(&sql, p, eaten, val);
    }
 
    return sql;
}
 
static void
getQueryParams(Variables *variables, const Command *command,
               const char **params)
{
    int         i;
 
    for (i = 0; i < command->argc - 1; i++)
        params[i] = getVariable(variables, command->argv[i + 1]);
}
 
static char *
valueTypeName(PgBenchValue *pval)
{
    if (pval->type == PGBT_NO_VALUE)
        return "none";
    else if (pval->type == PGBT_NULL)
        return "null";
    else if (pval->type == PGBT_INT)
        return "int";
    else if (pval->type == PGBT_DOUBLE)
        return "double";
    else if (pval->type == PGBT_BOOLEAN)
        return "boolean";
    else
    {
        /* internal error, should never get there */
        Assert(false);
        return NULL;
    }
}
 
/* get a value as a boolean, or tell if there is a problem */
static bool
coerceToBool(PgBenchValue *pval, bool *bval)
{
    if (pval->type == PGBT_BOOLEAN)
    {
        *bval = pval->u.bval;
        return true;
    }
    else                        /* NULL, INT or DOUBLE */
    {
        pg_log_error("cannot coerce %s to boolean", valueTypeName(pval));
        *bval = false;          /* suppress uninitialized-variable warnings */
        return false;
    }
}
 
/*
 * Return true or false from an expression for conditional purposes.
 * Non zero numerical values are true, zero and NULL are false.
 */
static bool
valueTruth(PgBenchValue *pval)
{
    switch (pval->type)
    {
        case PGBT_NULL:
            return false;
        case PGBT_BOOLEAN:
            return pval->u.bval;
        case PGBT_INT:
            return pval->u.ival != 0;
        case PGBT_DOUBLE:
            return pval->u.dval != 0.0;
        default:
            /* internal error, unexpected type */
            Assert(0);
            return false;
    }
}
 
/* get a value as an int, tell if there is a problem */
static bool
coerceToInt(PgBenchValue *pval, int64 *ival)
{
    if (pval->type == PGBT_INT)
    {
        *ival = pval->u.ival;
        return true;
    }
    else if (pval->type == PGBT_DOUBLE)
    {
        double      dval = rint(pval->u.dval);
 
        if (isnan(dval) || !FLOAT8_FITS_IN_INT64(dval))
        {
            pg_log_error("double to int overflow for %f", dval);
            return false;
        }
        *ival = (int64) dval;
        return true;
    }
    else                        /* BOOLEAN or NULL */
    {
        pg_log_error("cannot coerce %s to int", valueTypeName(pval));
        return false;
    }
}
 
/* get a value as a double, or tell if there is a problem */
static bool
coerceToDouble(PgBenchValue *pval, double *dval)
{
    if (pval->type == PGBT_DOUBLE)
    {
        *dval = pval->u.dval;
        return true;
    }
    else if (pval->type == PGBT_INT)
    {
        *dval = (double) pval->u.ival;
        return true;
    }
    else                        /* BOOLEAN or NULL */
    {
        pg_log_error("cannot coerce %s to double", valueTypeName(pval));
        return false;
    }
}
 
/* assign a null value */
static void
setNullValue(PgBenchValue *pv)
{
    pv->type = PGBT_NULL;
    pv->u.ival = 0;
}
 
/* assign a boolean value */
static void
setBoolValue(PgBenchValue *pv, bool bval)
{
    pv->type = PGBT_BOOLEAN;
    pv->u.bval = bval;
}
 
/* assign an integer value */
static void
setIntValue(PgBenchValue *pv, int64 ival)
{
    pv->type = PGBT_INT;
    pv->u.ival = ival;
}
 
/* assign a double value */
static void
setDoubleValue(PgBenchValue *pv, double dval)
{
    pv->type = PGBT_DOUBLE;
    pv->u.dval = dval;
}
 
static bool
isLazyFunc(PgBenchFunction func)
{
    return func == PGBENCH_AND || func == PGBENCH_OR || func == PGBENCH_CASE;
}
 
/* lazy evaluation of some functions */
static bool
evalLazyFunc(CState *st,
             PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
{
    PgBenchValue a1,
                a2;
    bool        ba1,
                ba2;
 
    Assert(isLazyFunc(func) && args != NULL && args->next != NULL);
 
    /* args points to first condition */
    if (!evaluateExpr(st, args->expr, &a1))
        return false;
 
    /* second condition for AND/OR and corresponding branch for CASE */
    args = args->next;
 
    switch (func)
    {
        case PGBENCH_AND:
            if (a1.type == PGBT_NULL)
            {
                setNullValue(retval);
                return true;
            }
 
            if (!coerceToBool(&a1, &ba1))
                return false;
 
            if (!ba1)
            {
                setBoolValue(retval, false);
                return true;
            }
 
            if (!evaluateExpr(st, args->expr, &a2))
                return false;
 
            if (a2.type == PGBT_NULL)
            {
                setNullValue(retval);
                return true;
            }
            else if (!coerceToBool(&a2, &ba2))
                return false;
            else
            {
                setBoolValue(retval, ba2);
                return true;
            }
 
            return true;
 
        case PGBENCH_OR:
 
            if (a1.type == PGBT_NULL)
            {
                setNullValue(retval);
                return true;
            }
 
            if (!coerceToBool(&a1, &ba1))
                return false;
 
            if (ba1)
            {
                setBoolValue(retval, true);
                return true;
            }
 
            if (!evaluateExpr(st, args->expr, &a2))
                return false;
 
            if (a2.type == PGBT_NULL)
            {
                setNullValue(retval);
                return true;
            }
            else if (!coerceToBool(&a2, &ba2))
                return false;
            else
            {
                setBoolValue(retval, ba2);
                return true;
            }
 
        case PGBENCH_CASE:
            /* when true, execute branch */
            if (valueTruth(&a1))
                return evaluateExpr(st, args->expr, retval);
 
            /* now args contains next condition or final else expression */
            args = args->next;
 
            /* final else case? */
            if (args->next == NULL)
                return evaluateExpr(st, args->expr, retval);
 
            /* no, another when, proceed */
            return evalLazyFunc(st, PGBENCH_CASE, args, retval);
 
        default:
            /* internal error, cannot get here */
            Assert(0);
            break;
    }
    return false;
}
 
/* maximum number of function arguments */
#define MAX_FARGS 16
 
/*
 * Recursive evaluation of standard functions,
 * which do not require lazy evaluation.
 */
static bool
evalStandardFunc(CState *st,
                 PgBenchFunction func, PgBenchExprLink *args,
                 PgBenchValue *retval)
{
    /* evaluate all function arguments */
    int         nargs = 0;
    PgBenchExprLink *l = args;
    bool        has_null = false;
 
    /*
     * This value is double braced to workaround GCC bug 53119, which seems to
     * exist at least on gcc (Debian 4.7.2-5) 4.7.2, 32-bit.
     */
    PgBenchValue vargs[MAX_FARGS] = {{0}};
 
    for (nargs = 0; nargs < MAX_FARGS && l != NULL; nargs++, l = l->next)
    {
        if (!evaluateExpr(st, l->expr, &vargs[nargs]))
            return false;
        has_null |= vargs[nargs].type == PGBT_NULL;
    }
 
    if (l != NULL)
    {
        pg_log_error("too many function arguments, maximum is %d", MAX_FARGS);
        return false;
    }
 
    /* NULL arguments */
    if (has_null && func != PGBENCH_IS && func != PGBENCH_DEBUG)
    {
        setNullValue(retval);
        return true;
    }
 
    /* then evaluate function */
    switch (func)
    {
            /* overloaded operators */
        case PGBENCH_ADD:
        case PGBENCH_SUB:
        case PGBENCH_MUL:
        case PGBENCH_DIV:
        case PGBENCH_MOD:
        case PGBENCH_EQ:
        case PGBENCH_NE:
        case PGBENCH_LE:
        case PGBENCH_LT:
            {
                PgBenchValue *lval = &vargs[0],
                           *rval = &vargs[1];
 
                Assert(nargs == 2);
 
                /* overloaded type management, double if some double */
                if ((lval->type == PGBT_DOUBLE ||
                     rval->type == PGBT_DOUBLE) && func != PGBENCH_MOD)
                {
                    double      ld,
                                rd;
 
                    if (!coerceToDouble(lval, &ld) ||
                        !coerceToDouble(rval, &rd))
                        return false;
 
                    switch (func)
                    {
                        case PGBENCH_ADD:
                            setDoubleValue(retval, ld + rd);
                            return true;
 
                        case PGBENCH_SUB:
                            setDoubleValue(retval, ld - rd);
                            return true;
 
                        case PGBENCH_MUL:
                            setDoubleValue(retval, ld * rd);
                            return true;
 
                        case PGBENCH_DIV:
                            setDoubleValue(retval, ld / rd);
                            return true;
 
                        case PGBENCH_EQ:
                            setBoolValue(retval, ld == rd);
                            return true;
 
                        case PGBENCH_NE:
                            setBoolValue(retval, ld != rd);
                            return true;
 
                        case PGBENCH_LE:
                            setBoolValue(retval, ld <= rd);
                            return true;
 
                        case PGBENCH_LT:
                            setBoolValue(retval, ld < rd);
                            return true;
 
                        default:
                            /* cannot get here */
                            Assert(0);
                    }
                }
                else            /* we have integer operands, or % */
                {
                    int64       li,
                                ri,
                                res;
 
                    if (!coerceToInt(lval, &li) ||
                        !coerceToInt(rval, &ri))
                        return false;
 
                    switch (func)
                    {
                        case PGBENCH_ADD:
                            if (pg_add_s64_overflow(li, ri, &res))
                            {
                                pg_log_error("bigint add out of range");
                                return false;
                            }
                            setIntValue(retval, res);
                            return true;
 
                        case PGBENCH_SUB:
                            if (pg_sub_s64_overflow(li, ri, &res))
                            {
                                pg_log_error("bigint sub out of range");
                                return false;
                            }
                            setIntValue(retval, res);
                            return true;
 
                        case PGBENCH_MUL:
                            if (pg_mul_s64_overflow(li, ri, &res))
                            {
                                pg_log_error("bigint mul out of range");
                                return false;
                            }
                            setIntValue(retval, res);
                            return true;
 
                        case PGBENCH_EQ:
                            setBoolValue(retval, li == ri);
                            return true;
 
                        case PGBENCH_NE:
                            setBoolValue(retval, li != ri);
                            return true;
 
                        case PGBENCH_LE:
                            setBoolValue(retval, li <= ri);
                            return true;
 
                        case PGBENCH_LT:
                            setBoolValue(retval, li < ri);
                            return true;
 
                        case PGBENCH_DIV:
                        case PGBENCH_MOD:
                            if (ri == 0)
                            {
                                pg_log_error("division by zero");
                                return false;
                            }
                            /* special handling of -1 divisor */
                            if (ri == -1)
                            {
                                if (func == PGBENCH_DIV)
                                {
                                    /* overflow check (needed for INT64_MIN) */
                                    if (li == PG_INT64_MIN)
                                    {
                                        pg_log_error("bigint div out of range");
                                        return false;
                                    }
                                    else
                                        setIntValue(retval, -li);
                                }
                                else
                                    setIntValue(retval, 0);
                                return true;
                            }
                            /* else divisor is not -1 */
                            if (func == PGBENCH_DIV)
                                setIntValue(retval, li / ri);
                            else    /* func == PGBENCH_MOD */
                                setIntValue(retval, li % ri);
 
                            return true;
 
                        default:
                            /* cannot get here */
                            Assert(0);
                    }
                }
 
                Assert(0);
                return false;   /* NOTREACHED */
            }
 
            /* integer bitwise operators */
        case PGBENCH_BITAND:
        case PGBENCH_BITOR:
        case PGBENCH_BITXOR:
        case PGBENCH_LSHIFT:
        case PGBENCH_RSHIFT:
            {
                int64       li,
                            ri;
 
                if (!coerceToInt(&vargs[0], &li) || !coerceToInt(&vargs[1], &ri))
                    return false;
 
                if (func == PGBENCH_BITAND)
                    setIntValue(retval, li & ri);
                else if (func == PGBENCH_BITOR)
                    setIntValue(retval, li | ri);
                else if (func == PGBENCH_BITXOR)
                    setIntValue(retval, li ^ ri);
                else if (func == PGBENCH_LSHIFT)
                    setIntValue(retval, li << ri);
                else if (func == PGBENCH_RSHIFT)
                    setIntValue(retval, li >> ri);
                else            /* cannot get here */
                    Assert(0);
 
                return true;
            }
 
            /* logical operators */
        case PGBENCH_NOT:
            {
                bool        b;
 
                if (!coerceToBool(&vargs[0], &b))
                    return false;
 
                setBoolValue(retval, !b);
                return true;
            }
 
            /* no arguments */
        case PGBENCH_PI:
            setDoubleValue(retval, M_PI);
            return true;
 
            /* 1 overloaded argument */
        case PGBENCH_ABS:
            {
                PgBenchValue *varg = &vargs[0];
 
                Assert(nargs == 1);
 
                if (varg->type == PGBT_INT)
                {
                    int64       i = varg->u.ival;
 
                    setIntValue(retval, i < 0 ? -i : i);
                }
                else
                {
                    double      d = varg->u.dval;
 
                    Assert(varg->type == PGBT_DOUBLE);
                    setDoubleValue(retval, d < 0.0 ? -d : d);
                }
 
                return true;
            }
 
        case PGBENCH_DEBUG:
            {
                PgBenchValue *varg = &vargs[0];
 
                Assert(nargs == 1);
 
                fprintf(stderr, "debug(script=%d,command=%d): ",
                        st->use_file, st->command + 1);
 
                if (varg->type == PGBT_NULL)
                    fprintf(stderr, "null\n");
                else if (varg->type == PGBT_BOOLEAN)
                    fprintf(stderr, "boolean %s\n", varg->u.bval ? "true" : "false");
                else if (varg->type == PGBT_INT)
                    fprintf(stderr, "int " INT64_FORMAT "\n", varg->u.ival);
                else if (varg->type == PGBT_DOUBLE)
                    fprintf(stderr, "double %.*g\n", DBL_DIG, varg->u.dval);
                else            /* internal error, unexpected type */
                    Assert(0);
 
                *retval = *varg;
 
                return true;
            }
 
            /* 1 double argument */
        case PGBENCH_DOUBLE:
        case PGBENCH_SQRT:
        case PGBENCH_LN:
        case PGBENCH_EXP:
            {
                double      dval;
 
                Assert(nargs == 1);
 
                if (!coerceToDouble(&vargs[0], &dval))
                    return false;
 
                if (func == PGBENCH_SQRT)
                    dval = sqrt(dval);
                else if (func == PGBENCH_LN)
                    dval = log(dval);
                else if (func == PGBENCH_EXP)
                    dval = exp(dval);
                /* else is cast: do nothing */
 
                setDoubleValue(retval, dval);
                return true;
            }
 
            /* 1 int argument */
        case PGBENCH_INT:
            {
                int64       ival;
 
                Assert(nargs == 1);
 
                if (!coerceToInt(&vargs[0], &ival))
                    return false;
 
                setIntValue(retval, ival);
                return true;
            }
 
            /* variable number of arguments */
        case PGBENCH_LEAST:
        case PGBENCH_GREATEST:
            {
                bool        havedouble;
                int         i;
 
                Assert(nargs >= 1);
 
                /* need double result if any input is double */
                havedouble = false;
                for (i = 0; i < nargs; i++)
                {
                    if (vargs[i].type == PGBT_DOUBLE)
                    {
                        havedouble = true;
                        break;
                    }
                }
                if (havedouble)
                {
                    double      extremum;
 
                    if (!coerceToDouble(&vargs[0], &extremum))
                        return false;
                    for (i = 1; i < nargs; i++)
                    {
                        double      dval;
 
                        if (!coerceToDouble(&vargs[i], &dval))
                            return false;
                        if (func == PGBENCH_LEAST)
                            extremum = Min(extremum, dval);
                        else
                            extremum = Max(extremum, dval);
                    }
                    setDoubleValue(retval, extremum);
                }
                else
                {
                    int64       extremum;
 
                    if (!coerceToInt(&vargs[0], &extremum))
                        return false;
                    for (i = 1; i < nargs; i++)
                    {
                        int64       ival;
 
                        if (!coerceToInt(&vargs[i], &ival))
                            return false;
                        if (func == PGBENCH_LEAST)
                            extremum = Min(extremum, ival);
                        else
                            extremum = Max(extremum, ival);
                    }
                    setIntValue(retval, extremum);
                }
                return true;
            }
 
            /* random functions */
        case PGBENCH_RANDOM:
        case PGBENCH_RANDOM_EXPONENTIAL:
        case PGBENCH_RANDOM_GAUSSIAN:
        case PGBENCH_RANDOM_ZIPFIAN:
            {
                int64       imin,
                            imax,
                            delta;
 
                Assert(nargs >= 2);
 
                if (!coerceToInt(&vargs[0], &imin) ||
                    !coerceToInt(&vargs[1], &imax))
                    return false;
 
                /* check random range */
                if (unlikely(imin > imax))
                {
                    pg_log_error("empty range given to random");
                    return false;
                }
                else if (unlikely(pg_sub_s64_overflow(imax, imin, &delta) ||
                                  pg_add_s64_overflow(delta, 1, &delta)))
                {
                    /* prevent int overflows in random functions */
                    pg_log_error("random range is too large");
                    return false;
                }
 
                if (func == PGBENCH_RANDOM)
                {
                    Assert(nargs == 2);
                    setIntValue(retval, getrand(&st->cs_func_rs, imin, imax));
                }
                else            /* gaussian & exponential */
                {
                    double      param;
 
                    Assert(nargs == 3);
 
                    if (!coerceToDouble(&vargs[2], &param))
                        return false;
 
                    if (func == PGBENCH_RANDOM_GAUSSIAN)
                    {
                        if (param < MIN_GAUSSIAN_PARAM)
                        {
                            pg_log_error("gaussian parameter must be at least %f (not %f)",
                                         MIN_GAUSSIAN_PARAM, param);
                            return false;
                        }
 
                        setIntValue(retval,
                                    getGaussianRand(&st->cs_func_rs,
                                                    imin, imax, param));
                    }
                    else if (func == PGBENCH_RANDOM_ZIPFIAN)
                    {
                        if (param < MIN_ZIPFIAN_PARAM || param > MAX_ZIPFIAN_PARAM)
                        {
                            pg_log_error("zipfian parameter must be in range [%.3f, %.0f] (not %f)",
                                         MIN_ZIPFIAN_PARAM, MAX_ZIPFIAN_PARAM, param);
                            return false;
                        }
 
                        setIntValue(retval,
                                    getZipfianRand(&st->cs_func_rs, imin, imax, param));
                    }
                    else        /* exponential */
                    {
                        if (param <= 0.0)
                        {
                            pg_log_error("exponential parameter must be greater than zero (not %f)",
                                         param);
                            return false;
                        }
 
                        setIntValue(retval,
                                    getExponentialRand(&st->cs_func_rs,
                                                       imin, imax, param));
                    }
                }
 
                return true;
            }
 
        case PGBENCH_POW:
            {
                PgBenchValue *lval = &vargs[0];
                PgBenchValue *rval = &vargs[1];
                double      ld,
                            rd;
 
                Assert(nargs == 2);
 
                if (!coerceToDouble(lval, &ld) ||
                    !coerceToDouble(rval, &rd))
                    return false;
 
                setDoubleValue(retval, pow(ld, rd));
 
                return true;
            }
 
        case PGBENCH_IS:
            {
                Assert(nargs == 2);
 
                /*
                 * note: this simple implementation is more permissive than
                 * SQL
                 */
                setBoolValue(retval,
                             vargs[0].type == vargs[1].type &&
                             vargs[0].u.bval == vargs[1].u.bval);
                return true;
            }
 
            /* hashing */
        case PGBENCH_HASH_FNV1A:
        case PGBENCH_HASH_MURMUR2:
            {
                int64       val,
                            seed;
 
                Assert(nargs == 2);
 
                if (!coerceToInt(&vargs[0], &val) ||
                    !coerceToInt(&vargs[1], &seed))
                    return false;
 
                if (func == PGBENCH_HASH_MURMUR2)
                    setIntValue(retval, getHashMurmur2(val, seed));
                else if (func == PGBENCH_HASH_FNV1A)
                    setIntValue(retval, getHashFnv1a(val, seed));
                else
                    /* cannot get here */
                    Assert(0);
 
                return true;
            }
 
        case PGBENCH_PERMUTE:
            {
                int64       val,
                            size,
                            seed;
 
                Assert(nargs == 3);
 
                if (!coerceToInt(&vargs[0], &val) ||
                    !coerceToInt(&vargs[1], &size) ||
                    !coerceToInt(&vargs[2], &seed))
                    return false;
 
                if (size <= 0)
                {
                    pg_log_error("permute size parameter must be greater than zero");
                    return false;
                }
 
                setIntValue(retval, permute(val, size, seed));
                return true;
            }
 
        default:
            /* cannot get here */
            Assert(0);
            /* dead code to avoid a compiler warning */
            return false;
    }
}
 
/* evaluate some function */
static bool
evalFunc(CState *st,
         PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
{
    if (isLazyFunc(func))
        return evalLazyFunc(st, func, args, retval);
    else
        return evalStandardFunc(st, func, args, retval);
}
 
/*
 * Recursive evaluation of an expression in a pgbench script
 * using the current state of variables.
 * Returns whether the evaluation was ok,
 * the value itself is returned through the retval pointer.
 */
static bool
evaluateExpr(CState *st, PgBenchExpr *expr, PgBenchValue *retval)
{
    switch (expr->etype)
    {
        case ENODE_CONSTANT:
            {
                *retval = expr->u.constant;
                return true;
            }
 
        case ENODE_VARIABLE:
            {
                Variable   *var;
 
                if ((var = lookupVariable(&st->variables, expr->u.variable.varname)) == NULL)
                {
                    pg_log_error("undefined variable \"%s\"", expr->u.variable.varname);
                    return false;
                }
 
                if (!makeVariableValue(var))
                    return false;
 
                *retval = var->value;
                return true;
            }
 
        case ENODE_FUNCTION:
            return evalFunc(st,
                            expr->u.function.function,
                            expr->u.function.args,
                            retval);
 
        default:
            /* internal error which should never occur */
            pg_fatal("unexpected enode type in evaluation: %d", expr->etype);
    }
}
 
/*
 * Convert command name to meta-command enum identifier
 */
static MetaCommand
getMetaCommand(const char *cmd)
{
    MetaCommand mc;
 
    if (cmd == NULL)
        mc = META_NONE;
    else if (pg_strcasecmp(cmd, "set") == 0)
        mc = META_SET;
    else if (pg_strcasecmp(cmd, "setshell") == 0)
        mc = META_SETSHELL;
    else if (pg_strcasecmp(cmd, "shell") == 0)
        mc = META_SHELL;
    else if (pg_strcasecmp(cmd, "sleep") == 0)
        mc = META_SLEEP;
    else if (pg_strcasecmp(cmd, "if") == 0)
        mc = META_IF;
    else if (pg_strcasecmp(cmd, "elif") == 0)
        mc = META_ELIF;
    else if (pg_strcasecmp(cmd, "else") == 0)
        mc = META_ELSE;
    else if (pg_strcasecmp(cmd, "endif") == 0)
        mc = META_ENDIF;
    else if (pg_strcasecmp(cmd, "gset") == 0)
        mc = META_GSET;
    else if (pg_strcasecmp(cmd, "aset") == 0)
        mc = META_ASET;
    else if (pg_strcasecmp(cmd, "startpipeline") == 0)
        mc = META_STARTPIPELINE;
    else if (pg_strcasecmp(cmd, "syncpipeline") == 0)
        mc = META_SYNCPIPELINE;
    else if (pg_strcasecmp(cmd, "endpipeline") == 0)
        mc = META_ENDPIPELINE;
    else
        mc = META_NONE;
    return mc;
}
 
/*
 * Run a shell command. The result is assigned to the variable if not NULL.
 * Return true if succeeded, or false on error.
 */
static bool
runShellCommand(Variables *variables, char *variable, char **argv, int argc)
{
    char        command[SHELL_COMMAND_SIZE];
    int         i,
                len = 0;
    FILE       *fp;
    char        res[64];
    char       *endptr;
    int         retval;
 
    /*----------
     * Join arguments with whitespace separators. Arguments starting with
     * exactly one colon are treated as variables:
     *  name - append a string "name"
     *  :var - append a variable named 'var'
     *  ::name - append a string ":name"
     *----------
     */
    for (i = 0; i < argc; i++)
    {
        char       *arg;
        int         arglen;
 
        if (argv[i][0] != ':')
        {
            arg = argv[i];      /* a string literal */
        }
        else if (argv[i][1] == ':')
        {
            arg = argv[i] + 1;  /* a string literal starting with colons */
        }
        else if ((arg = getVariable(variables, argv[i] + 1)) == NULL)
        {
            pg_log_error("%s: undefined variable \"%s\"", argv[0], argv[i]);
            return false;
        }
 
        arglen = strlen(arg);
        if (len + arglen + (i > 0 ? 1 : 0) >= SHELL_COMMAND_SIZE - 1)
        {
            pg_log_error("%s: shell command is too long", argv[0]);
            return false;
        }
 
        if (i > 0)
            command[len++] = ' ';
        memcpy(command + len, arg, arglen);
        len += arglen;
    }
 
    command[len] = '\0';
 
    fflush(NULL);               /* needed before either system() or popen() */
 
    /* Fast path for non-assignment case */
    if (variable == NULL)
    {
        if (system(command))
        {
            if (!timer_exceeded)
                pg_log_error("%s: could not launch shell command", argv[0]);
            return false;
        }
        return true;
    }
 
    /* Execute the command with pipe and read the standard output. */
    if ((fp = popen(command, "r")) == NULL)
    {
        pg_log_error("%s: could not launch shell command", argv[0]);
        return false;
    }
    if (fgets(res, sizeof(res), fp) == NULL)
    {
        if (!timer_exceeded)
            pg_log_error("%s: could not read result of shell command", argv[0]);
        (void) pclose(fp);
        return false;
    }
    if (pclose(fp) < 0)
    {
        pg_log_error("%s: could not run shell command: %m", argv[0]);
        return false;
    }
 
    /* Check whether the result is an integer and assign it to the variable */
    retval = (int) strtol(res, &endptr, 10);
    while (*endptr != '\0' && isspace((unsigned char) *endptr))
        endptr++;
    if (*res == '\0' || *endptr != '\0')
    {
        pg_log_error("%s: shell command must return an integer (not \"%s\")", argv[0], res);
        return false;
    }
    if (!putVariableInt(variables, "setshell", variable, retval))
        return false;
 
    pg_log_debug("%s: shell parameter name: \"%s\", value: \"%s\"", argv[0], argv[1], res);
 
    return true;
}
 
/*
 * Report the abortion of the client when processing SQL commands.
 */
static void
commandFailed(CState *st, const char *cmd, const char *message)
{
    pg_log_error("client %d aborted in command %d (%s) of script %d; %s",
                 st->id, st->command, cmd, st->use_file, message);
}
 
/*
 * Report the error in the command while the script is executing.
 */
static void
commandError(CState *st, const char *message)
{
    Assert(sql_script[st->use_file].commands[st->command]->type == SQL_COMMAND);
    pg_log_info("client %d got an error in command %d (SQL) of script %d; %s",
                st->id, st->command, st->use_file, message);
}
 
/* return a script number with a weighted choice. */
static int
chooseScript(TState *thread)
{
    int         i = 0;
    int64       w;
 
    if (num_scripts == 1)
        return 0;
 
    w = getrand(&thread->ts_choose_rs, 0, total_weight - 1);
    do
    {
        w -= sql_script[i++].weight;
    } while (w >= 0);
 
    return i - 1;
}
 
/*
 * Allocate space for CState->prepared: we need one boolean for each command
 * of each script.
 */
static void
allocCStatePrepared(CState *st)
{
    Assert(st->prepared == NULL);
 
    st->prepared = pg_malloc(sizeof(bool *) * num_scripts);
    for (int i = 0; i < num_scripts; i++)
    {
        ParsedScript *script = &sql_script[i];
        int         numcmds;
 
        for (numcmds = 0; script->commands[numcmds] != NULL; numcmds++)
            ;
        st->prepared[i] = pg_malloc0(sizeof(bool) * numcmds);
    }
}
 
/*
 * Prepare the SQL command from st->use_file at command_num.
 */
static void
prepareCommand(CState *st, int command_num)
{
    Command    *command = sql_script[st->use_file].commands[command_num];
 
    /* No prepare for non-SQL commands */
    if (command->type != SQL_COMMAND)
        return;
 
    if (!st->prepared)
        allocCStatePrepared(st);
 
    if (!st->prepared[st->use_file][command_num])
    {
        PGresult   *res;
 
        pg_log_debug("client %d preparing %s", st->id, command->prepname);
        res = PQprepare(st->con, command->prepname,
                        command->argv[0], command->argc - 1, NULL);
        if (PQresultStatus(res) != PGRES_COMMAND_OK)
            pg_log_error("%s", PQerrorMessage(st->con));
        PQclear(res);
        st->prepared[st->use_file][command_num] = true;
    }
}
 
/*
 * Prepare all the commands in the script that come after the \startpipeline
 * that's at position st->command, and the first \endpipeline we find.
 *
 * This sets the ->prepared flag for each relevant command as well as the
 * \startpipeline itself, but doesn't move the st->command counter.
 */
static void
prepareCommandsInPipeline(CState *st)
{
    int         j;
    Command   **commands = sql_script[st->use_file].commands;
 
    Assert(commands[st->command]->type == META_COMMAND &&
           commands[st->command]->meta == META_STARTPIPELINE);
 
    if (!st->prepared)
        allocCStatePrepared(st);
 
    /*
     * We set the 'prepared' flag on the \startpipeline itself to flag that we
     * don't need to do this next time without calling prepareCommand(), even
     * though we don't actually prepare this command.
     */
    if (st->prepared[st->use_file][st->command])
        return;
 
    for (j = st->command + 1; commands[j] != NULL; j++)
    {
        if (commands[j]->type == META_COMMAND &&
            commands[j]->meta == META_ENDPIPELINE)
            break;
 
        prepareCommand(st, j);
    }
 
    st->prepared[st->use_file][st->command] = true;
}
 
/* Send a SQL command, using the chosen querymode */
static bool
sendCommand(CState *st, Command *command)
{
    int         r;
 
    if (querymode == QUERY_SIMPLE)
    {
        char       *sql;
 
        sql = pg_strdup(command->argv[0]);
        sql = assignVariables(&st->variables, sql);
 
        pg_log_debug("client %d sending %s", st->id, sql);
        r = PQsendQuery(st->con, sql);
        free(sql);
    }
    else if (querymode == QUERY_EXTENDED)
    {
        const char *sql = command->argv[0];
        const char *params[MAX_ARGS];
 
        getQueryParams(&st->variables, command, params);
 
        pg_log_debug("client %d sending %s", st->id, sql);
        r = PQsendQueryParams(st->con, sql, command->argc - 1,
                              NULL, params, NULL, NULL, 0);
    }
    else if (querymode == QUERY_PREPARED)
    {
        const char *params[MAX_ARGS];
 
        prepareCommand(st, st->command);
        getQueryParams(&st->variables, command, params);
 
        pg_log_debug("client %d sending %s", st->id, command->prepname);
        r = PQsendQueryPrepared(st->con, command->prepname, command->argc - 1,
                                params, NULL, NULL, 0);
    }
    else                        /* unknown sql mode */
        r = 0;
 
    if (r == 0)
    {
        pg_log_debug("client %d could not send %s", st->id, command->argv[0]);
        return false;
    }
    else
        return true;
}
 
/*
 * Get the error status from the error code.
 */
static EStatus
getSQLErrorStatus(const char *sqlState)
{
    if (sqlState != NULL)
    {
        if (strcmp(sqlState, ERRCODE_T_R_SERIALIZATION_FAILURE) == 0)
            return ESTATUS_SERIALIZATION_ERROR;
        else if (strcmp(sqlState, ERRCODE_T_R_DEADLOCK_DETECTED) == 0)
            return ESTATUS_DEADLOCK_ERROR;
    }
 
    return ESTATUS_OTHER_SQL_ERROR;
}
 
/*
 * Returns true if this type of error can be retried.
 */
static bool
canRetryError(EStatus estatus)
{
    return (estatus == ESTATUS_SERIALIZATION_ERROR ||
            estatus == ESTATUS_DEADLOCK_ERROR);
}
 
/*
 * Process query response from the backend.
 *
 * If varprefix is not NULL, it's the variable name prefix where to store
 * the results of the *last* command (META_GSET) or *all* commands
 * (META_ASET).
 *
 * Returns true if everything is A-OK, false if any error occurs.
 */
static bool
readCommandResponse(CState *st, MetaCommand meta, char *varprefix)
{
    PGresult   *res;
    PGresult   *next_res;
    int         qrynum = 0;
 
    /*
     * varprefix should be set only with \gset or \aset, and \endpipeline and
     * SQL commands do not need it.
     */
    Assert((meta == META_NONE && varprefix == NULL) ||
           ((meta == META_ENDPIPELINE) && varprefix == NULL) ||
           ((meta == META_GSET || meta == META_ASET) && varprefix != NULL));
 
    res = PQgetResult(st->con);
 
    while (res != NULL)
    {
        bool        is_last;
 
        /* peek at the next result to know whether the current is last */
        next_res = PQgetResult(st->con);
        is_last = (next_res == NULL);
 
        switch (PQresultStatus(res))
        {
            case PGRES_COMMAND_OK:  /* non-SELECT commands */
            case PGRES_EMPTY_QUERY: /* may be used for testing no-op overhead */
                if (is_last && meta == META_GSET)
                {
                    pg_log_error("client %d script %d command %d query %d: expected one row, got %d",
                                 st->id, st->use_file, st->command, qrynum, 0);
                    st->estatus = ESTATUS_META_COMMAND_ERROR;
                    goto error;
                }
                break;
 
            case PGRES_TUPLES_OK:
                if ((is_last && meta == META_GSET) || meta == META_ASET)
                {
                    int         ntuples = PQntuples(res);
 
                    if (meta == META_GSET && ntuples != 1)
                    {
                        /* under \gset, report the error */
                        pg_log_error("client %d script %d command %d query %d: expected one row, got %d",
                                     st->id, st->use_file, st->command, qrynum, PQntuples(res));
                        st->estatus = ESTATUS_META_COMMAND_ERROR;
                        goto error;
                    }
                    else if (meta == META_ASET && ntuples <= 0)
                    {
                        /* coldly skip empty result under \aset */
                        break;
                    }
 
                    /* store results into variables */
                    for (int fld = 0; fld < PQnfields(res); fld++)
                    {
                        char       *varname = PQfname(res, fld);
 
                        /* allocate varname only if necessary, freed below */
                        if (*varprefix != '\0')
                            varname = psprintf("%s%s", varprefix, varname);
 
                        /* store last row result as a string */
                        if (!putVariable(&st->variables, meta == META_ASET ? "aset" : "gset", varname,
                                         PQgetvalue(res, ntuples - 1, fld)))
                        {
                            /* internal error */
                            pg_log_error("client %d script %d command %d query %d: error storing into variable %s",
                                         st->id, st->use_file, st->command, qrynum, varname);
                            st->estatus = ESTATUS_META_COMMAND_ERROR;
                            goto error;
                        }
 
                        if (*varprefix != '\0')
                            pg_free(varname);
                    }
                }
                /* otherwise the result is simply thrown away by PQclear below */
                break;
 
            case PGRES_PIPELINE_SYNC:
                pg_log_debug("client %d pipeline ending, ongoing syncs: %d",
                             st->id, st->num_syncs);
                st->num_syncs--;
                if (st->num_syncs == 0 && PQexitPipelineMode(st->con) != 1)
                    pg_log_error("client %d failed to exit pipeline mode: %s", st->id,
                                 PQerrorMessage(st->con));
                break;
 
            case PGRES_NONFATAL_ERROR:
            case PGRES_FATAL_ERROR:
                st->estatus = getSQLErrorStatus(PQresultErrorField(res,
                                                                   PG_DIAG_SQLSTATE));
                if (canRetryError(st->estatus))
                {
                    if (verbose_errors)
                        commandError(st, PQerrorMessage(st->con));
                    goto error;
                }
                /* fall through */
 
            default:
                /* anything else is unexpected */
                pg_log_error("client %d script %d aborted in command %d query %d: %s",
                             st->id, st->use_file, st->command, qrynum,
                             PQerrorMessage(st->con));
                goto error;
        }
 
        PQclear(res);
        qrynum++;
        res = next_res;
    }
 
    if (qrynum == 0)
    {
        pg_log_error("client %d command %d: no results", st->id, st->command);
        return false;
    }
 
    return true;
 
error:
    PQclear(res);
    PQclear(next_res);
    do
    {
        res = PQgetResult(st->con);
        PQclear(res);
    } while (res);
 
    return false;
}
 
/*
 * Parse the argument to a \sleep command, and return the requested amount
 * of delay, in microseconds.  Returns true on success, false on error.
 */
static bool
evaluateSleep(Variables *variables, int argc, char **argv, int *usecs)
{
    char       *var;
    int         usec;
 
    if (*argv[1] == ':')
    {
        if ((var = getVariable(variables, argv[1] + 1)) == NULL)
        {
            pg_log_error("%s: undefined variable \"%s\"", argv[0], argv[1] + 1);
            return false;
        }
 
        usec = atoi(var);
 
        /* Raise an error if the value of a variable is not a number */
        if (usec == 0 && !isdigit((unsigned char) *var))
        {
            pg_log_error("%s: invalid sleep time \"%s\" for variable \"%s\"",
                         argv[0], var, argv[1] + 1);
            return false;
        }
    }
    else
        usec = atoi(argv[1]);
 
    if (argc > 2)
    {
        if (pg_strcasecmp(argv[2], "ms") == 0)
            usec *= 1000;
        else if (pg_strcasecmp(argv[2], "s") == 0)
            usec *= 1000000;
    }
    else
        usec *= 1000000;
 
    *usecs = usec;
    return true;
}
 
 
/*
 * Returns true if the error can be retried.
 */
static bool
doRetry(CState *st, pg_time_usec_t *now)
{
    Assert(st->estatus != ESTATUS_NO_ERROR);
 
    /* We can only retry serialization or deadlock errors. */
    if (!canRetryError(st->estatus))
        return false;
 
    /*
     * We must have at least one option to limit the retrying of transactions
     * that got an error.
     */
    Assert(max_tries || latency_limit || duration > 0);
 
    /*
     * We cannot retry the error if we have reached the maximum number of
     * tries.
     */
    if (max_tries && st->tries >= max_tries)
        return false;
 
    /*
     * We cannot retry the error if we spent too much time on this
     * transaction.
     */
    if (latency_limit)
    {
        pg_time_now_lazy(now);
        if (*now - st->txn_scheduled > latency_limit)
            return false;
    }
 
    /*
     * We cannot retry the error if the benchmark duration is over.
     */
    if (timer_exceeded)
        return false;
 
    /* OK */
    return true;
}
 
/*
 * Read results and discard it until a sync point.
 */
static int
discardUntilSync(CState *st)
{
    /* send a sync */
    if (!PQpipelineSync(st->con))
    {
        pg_log_error("client %d aborted: failed to send a pipeline sync",
                     st->id);
        return 0;
    }
 
    /* receive PGRES_PIPELINE_SYNC and null following it */
    for (;;)
    {
        PGresult   *res = PQgetResult(st->con);
 
        if (PQresultStatus(res) == PGRES_PIPELINE_SYNC)
        {
            PQclear(res);
            res = PQgetResult(st->con);
            Assert(res == NULL);
            break;
        }
        PQclear(res);
    }
 
    /* exit pipeline */
    if (PQexitPipelineMode(st->con) != 1)
    {
        pg_log_error("client %d aborted: failed to exit pipeline mode for rolling back the failed transaction",
                     st->id);
        return 0;
    }
    return 1;
}
 
/*
 * Get the transaction status at the end of a command especially for
 * checking if we are in a (failed) transaction block.
 */
static TStatus
getTransactionStatus(PGconn *con)
{
    PGTransactionStatusType tx_status;
 
    tx_status = PQtransactionStatus(con);
    switch (tx_status)
    {
        case PQTRANS_IDLE:
            return TSTATUS_IDLE;
        case PQTRANS_INTRANS:
        case PQTRANS_INERROR:
            return TSTATUS_IN_BLOCK;
        case PQTRANS_UNKNOWN:
            /* PQTRANS_UNKNOWN is expected given a broken connection */
            if (PQstatus(con) == CONNECTION_BAD)
                return TSTATUS_CONN_ERROR;
            /* fall through */
        case PQTRANS_ACTIVE:
        default:
 
            /*
             * We cannot find out whether we are in a transaction block or
             * not. Internal error which should never occur.
             */
            pg_log_error("unexpected transaction status %d", tx_status);
            return TSTATUS_OTHER_ERROR;
    }
 
    /* not reached */
    Assert(false);
    return TSTATUS_OTHER_ERROR;
}
 
/*
 * Print verbose messages of an error
 */
static void
printVerboseErrorMessages(CState *st, pg_time_usec_t *now, bool is_retry)
{
    static PQExpBuffer buf = NULL;
 
    if (buf == NULL)
        buf = createPQExpBuffer();
    else
        resetPQExpBuffer(buf);
 
    printfPQExpBuffer(buf, "client %d ", st->id);
    appendPQExpBufferStr(buf, (is_retry ?
                               "repeats the transaction after the error" :
                               "ends the failed transaction"));
    appendPQExpBuffer(buf, " (try %u", st->tries);
 
    /* Print max_tries if it is not unlimited. */
    if (max_tries)
        appendPQExpBuffer(buf, "/%u", max_tries);
 
    /*
     * If the latency limit is used, print a percentage of the current
     * transaction latency from the latency limit.
     */
    if (latency_limit)
    {
        pg_time_now_lazy(now);
        appendPQExpBuffer(buf, ", %.3f%% of the maximum time of tries was used",
                          (100.0 * (*now - st->txn_scheduled) / latency_limit));
    }
    appendPQExpBufferStr(buf, ")\n");
 
    pg_log_info("%s", buf->data);
}
 
/*
 * Advance the state machine of a connection.
 */
static void
advanceConnectionState(TState *thread, CState *st, StatsData *agg)
{
 
    /*
     * gettimeofday() isn't free, so we get the current timestamp lazily the
     * first time it's needed, and reuse the same value throughout this
     * function after that.  This also ensures that e.g. the calculated
     * latency reported in the log file and in the totals are the same. Zero
     * means "not set yet".  Reset "now" when we execute shell commands or
     * expressions, which might take a non-negligible amount of time, though.
     */
    pg_time_usec_t now = 0;
 
    /*
     * Loop in the state machine, until we have to wait for a result from the
     * server or have to sleep for throttling or \sleep.
     *
     * Note: In the switch-statement below, 'break' will loop back here,
     * meaning "continue in the state machine".  Return is used to return to
     * the caller, giving the thread the opportunity to advance another
     * client.
     */
    for (;;)
    {
        Command    *command;
 
        switch (st->state)
        {
                /* Select transaction (script) to run.  */
            case CSTATE_CHOOSE_SCRIPT:
                st->use_file = chooseScript(thread);
                Assert(conditional_stack_empty(st->cstack));
 
                /* reset transaction variables to default values */
                st->estatus = ESTATUS_NO_ERROR;
                st->tries = 1;
 
                pg_log_debug("client %d executing script \"%s\"",
                             st->id, sql_script[st->use_file].desc);
 
                /*
                 * If time is over, we're done; otherwise, get ready to start
                 * a new transaction, or to get throttled if that's requested.
                 */
                st->state = timer_exceeded ? CSTATE_FINISHED :
                    throttle_delay > 0 ? CSTATE_PREPARE_THROTTLE : CSTATE_START_TX;
                break;
 
                /* Start new transaction (script) */
            case CSTATE_START_TX:
                pg_time_now_lazy(&now);
 
                /* establish connection if needed, i.e. under --connect */
                if (st->con == NULL)
                {
                    pg_time_usec_t start = now;
 
                    if ((st->con = doConnect()) == NULL)
                    {
                        /*
                         * as the bench is already running, we do not abort
                         * the process
                         */
                        pg_log_error("client %d aborted while establishing connection", st->id);
                        st->state = CSTATE_ABORTED;
                        break;
                    }
 
                    /* reset now after connection */
                    now = pg_time_now();
 
                    thread->conn_duration += now - start;
 
                    /* Reset session-local state */
                    pg_free(st->prepared);
                    st->prepared = NULL;
                }
 
                /*
                 * It is the first try to run this transaction. Remember the
                 * random state: maybe it will get an error and we will need
                 * to run it again.
                 */
                st->random_state = st->cs_func_rs;
 
                /* record transaction start time */
                st->txn_begin = now;
 
                /*
                 * When not throttling, this is also the transaction's
                 * scheduled start time.
                 */
                if (!throttle_delay)
                    st->txn_scheduled = now;
 
                /* Begin with the first command */
                st->state = CSTATE_START_COMMAND;
                st->command = 0;
                break;
 
                /*
                 * Handle throttling once per transaction by sleeping.
                 */
            case CSTATE_PREPARE_THROTTLE:
 
                /*
                 * Generate a delay such that the series of delays will
                 * approximate a Poisson distribution centered on the
                 * throttle_delay time.
                 *
                 * If transactions are too slow or a given wait is shorter
                 * than a transaction, the next transaction will start right
                 * away.
                 */
                Assert(throttle_delay > 0);
 
                thread->throttle_trigger +=
                    getPoissonRand(&thread->ts_throttle_rs, throttle_delay);
                st->txn_scheduled = thread->throttle_trigger;
 
                /*
                 * If --latency-limit is used, and this slot is already late
                 * so that the transaction will miss the latency limit even if
                 * it completed immediately, skip this time slot and loop to
                 * reschedule.
                 */
                if (latency_limit)
                {
                    pg_time_now_lazy(&now);
 
                    if (thread->throttle_trigger < now - latency_limit)
                    {
                        processXactStats(thread, st, &now, true, agg);
 
                        /*
                         * Finish client if -T or -t was exceeded.
                         *
                         * Stop counting skipped transactions under -T as soon
                         * as the timer is exceeded. Because otherwise it can
                         * take a very long time to count all of them
                         * especially when quite a lot of them happen with
                         * unrealistically high rate setting in -R, which
                         * would prevent pgbench from ending immediately.
                         * Because of this behavior, note that there is no
                         * guarantee that all skipped transactions are counted
                         * under -T though there is under -t. This is OK in
                         * practice because it's very unlikely to happen with
                         * realistic setting.
                         */
                        if (timer_exceeded || (nxacts > 0 && st->cnt >= nxacts))
                            st->state = CSTATE_FINISHED;
 
                        /* Go back to top of loop with CSTATE_PREPARE_THROTTLE */
                        break;
                    }
                }
 
                /*
                 * stop client if next transaction is beyond pgbench end of
                 * execution; otherwise, throttle it.
                 */
                st->state = end_time > 0 && st->txn_scheduled > end_time ?
                    CSTATE_FINISHED : CSTATE_THROTTLE;
                break;
 
                /*
                 * Wait until it's time to start next transaction.
                 */
            case CSTATE_THROTTLE:
                pg_time_now_lazy(&now);
 
                if (now < st->txn_scheduled)
                    return;     /* still sleeping, nothing to do here */
 
                /* done sleeping, but don't start transaction if we're done */
                st->state = timer_exceeded ? CSTATE_FINISHED : CSTATE_START_TX;
                break;
 
                /*
                 * Send a command to server (or execute a meta-command)
                 */
            case CSTATE_START_COMMAND:
                command = sql_script[st->use_file].commands[st->command];
 
                /*
                 * Transition to script end processing if done, but close up
                 * shop if a pipeline is open at this point.
                 */
                if (command == NULL)
                {
                    if (PQpipelineStatus(st->con) == PQ_PIPELINE_OFF)
                        st->state = CSTATE_END_TX;
                    else
                    {
                        pg_log_error("client %d aborted: end of script reached with pipeline open",
                                     st->id);
                        st->state = CSTATE_ABORTED;
                    }
 
                    break;
                }
 
                /* record begin time of next command, and initiate it */
                if (report_per_command)
                {
                    pg_time_now_lazy(&now);
                    st->stmt_begin = now;
                }
 
                /* Execute the command */
                if (command->type == SQL_COMMAND)
                {
                    /* disallow \aset and \gset in pipeline mode */
                    if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
                    {
                        if (command->meta == META_GSET)
                        {
                            commandFailed(st, "gset", "\\gset is not allowed in pipeline mode");
                            st->state = CSTATE_ABORTED;
                            break;
                        }
                        else if (command->meta == META_ASET)
                        {
                            commandFailed(st, "aset", "\\aset is not allowed in pipeline mode");
                            st->state = CSTATE_ABORTED;
                            break;
                        }
                    }
 
                    if (!sendCommand(st, command))
                    {
                        commandFailed(st, "SQL", "SQL command send failed");
                        st->state = CSTATE_ABORTED;
                    }
                    else
                    {
                        /* Wait for results, unless in pipeline mode */
                        if (PQpipelineStatus(st->con) == PQ_PIPELINE_OFF)
                            st->state = CSTATE_WAIT_RESULT;
                        else
                            st->state = CSTATE_END_COMMAND;
                    }
                }
                else if (command->type == META_COMMAND)
                {
                    /*-----
                     * Possible state changes when executing meta commands:
                     * - on errors CSTATE_ABORTED
                     * - on sleep CSTATE_SLEEP
                     * - else CSTATE_END_COMMAND
                     */
                    st->state = executeMetaCommand(st, &now);
                    if (st->state == CSTATE_ABORTED)
                        st->estatus = ESTATUS_META_COMMAND_ERROR;
                }
 
                /*
                 * We're now waiting for an SQL command to complete, or
                 * finished processing a metacommand, or need to sleep, or
                 * something bad happened.
                 */
                Assert(st->state == CSTATE_WAIT_RESULT ||
                       st->state == CSTATE_END_COMMAND ||
                       st->state == CSTATE_SLEEP ||
                       st->state == CSTATE_ABORTED);
                break;
 
                /*
                 * non executed conditional branch
                 */
            case CSTATE_SKIP_COMMAND:
                Assert(!conditional_active(st->cstack));
                /* quickly skip commands until something to do... */
                while (true)
                {
                    command = sql_script[st->use_file].commands[st->command];
 
                    /* cannot reach end of script in that state */
                    Assert(command != NULL);
 
                    /*
                     * if this is conditional related, update conditional
                     * state
                     */
                    if (command->type == META_COMMAND &&
                        (command->meta == META_IF ||
                         command->meta == META_ELIF ||
                         command->meta == META_ELSE ||
                         command->meta == META_ENDIF))
                    {
                        switch (conditional_stack_peek(st->cstack))
                        {
                            case IFSTATE_FALSE:
                                if (command->meta == META_IF ||
                                    command->meta == META_ELIF)
                                {
                                    /* we must evaluate the condition */
                                    st->state = CSTATE_START_COMMAND;
                                }
                                else if (command->meta == META_ELSE)
                                {
                                    /* we must execute next command */
                                    conditional_stack_poke(st->cstack,
                                                           IFSTATE_ELSE_TRUE);
                                    st->state = CSTATE_START_COMMAND;
                                    st->command++;
                                }
                                else if (command->meta == META_ENDIF)
                                {
                                    Assert(!conditional_stack_empty(st->cstack));
                                    conditional_stack_pop(st->cstack);
                                    if (conditional_active(st->cstack))
                                        st->state = CSTATE_START_COMMAND;
 
                                    /*
                                     * else state remains in
                                     * CSTATE_SKIP_COMMAND
                                     */
                                    st->command++;
                                }
                                break;
 
                            case IFSTATE_IGNORED:
                            case IFSTATE_ELSE_FALSE:
                                if (command->meta == META_IF)
                                    conditional_stack_push(st->cstack,
                                                           IFSTATE_IGNORED);
                                else if (command->meta == META_ENDIF)
                                {
                                    Assert(!conditional_stack_empty(st->cstack));
                                    conditional_stack_pop(st->cstack);
                                    if (conditional_active(st->cstack))
                                        st->state = CSTATE_START_COMMAND;
                                }
                                /* could detect "else" & "elif" after "else" */
                                st->command++;
                                break;
 
                            case IFSTATE_NONE:
                            case IFSTATE_TRUE:
                            case IFSTATE_ELSE_TRUE:
                            default:
 
                                /*
                                 * inconsistent if inactive, unreachable dead
                                 * code
                                 */
                                Assert(false);
                        }
                    }
                    else
                    {
                        /* skip and consider next */
                        st->command++;
                    }
 
                    if (st->state != CSTATE_SKIP_COMMAND)
                        /* out of quick skip command loop */
                        break;
                }
                break;
 
                /*
                 * Wait for the current SQL command to complete
                 */
            case CSTATE_WAIT_RESULT:
                pg_log_debug("client %d receiving", st->id);
 
                /*
                 * Only check for new network data if we processed all data
                 * fetched prior. Otherwise we end up doing a syscall for each
                 * individual pipelined query, which has a measurable
                 * performance impact.
                 */
                if (PQisBusy(st->con) && !PQconsumeInput(st->con))
                {
                    /* there's something wrong */
                    commandFailed(st, "SQL", "perhaps the backend died while processing");
                    st->state = CSTATE_ABORTED;
                    break;
                }
                if (PQisBusy(st->con))
                    return;     /* don't have the whole result yet */
 
                /* store or discard the query results */
                if (readCommandResponse(st,
                                        sql_script[st->use_file].commands[st->command]->meta,
                                        sql_script[st->use_file].commands[st->command]->varprefix))
                {
                    /*
                     * outside of pipeline mode: stop reading results.
                     * pipeline mode: continue reading results until an
                     * end-of-pipeline response.
                     */
                    if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
                        st->state = CSTATE_END_COMMAND;
                }
                else if (canRetryError(st->estatus))
                    st->state = CSTATE_ERROR;
                else
                    st->state = CSTATE_ABORTED;
                break;
 
                /*
                 * Wait until sleep is done. This state is entered after a
                 * \sleep metacommand. The behavior is similar to
                 * CSTATE_THROTTLE, but proceeds to CSTATE_START_COMMAND
                 * instead of CSTATE_START_TX.
                 */
            case CSTATE_SLEEP:
                pg_time_now_lazy(&now);
                if (now < st->sleep_until)
                    return;     /* still sleeping, nothing to do here */
                /* Else done sleeping. */
                st->state = CSTATE_END_COMMAND;
                break;
 
                /*
                 * End of command: record stats and proceed to next command.
                 */
            case CSTATE_END_COMMAND:
 
                /*
                 * command completed: accumulate per-command execution times
                 * in thread-local data structure, if per-command latencies
                 * are requested.
                 */
                if (report_per_command)
                {
                    pg_time_now_lazy(&now);
 
                    command = sql_script[st->use_file].commands[st->command];
                    /* XXX could use a mutex here, but we choose not to */
                    addToSimpleStats(&command->stats,
                                     PG_TIME_GET_DOUBLE(now - st->stmt_begin));
                }
 
                /* Go ahead with next command, to be executed or skipped */
                st->command++;
                st->state = conditional_active(st->cstack) ?
                    CSTATE_START_COMMAND : CSTATE_SKIP_COMMAND;
                break;
 
                /*
                 * Clean up after an error.
                 */
            case CSTATE_ERROR:
                {
                    TStatus     tstatus;
 
                    Assert(st->estatus != ESTATUS_NO_ERROR);
 
                    /* Clear the conditional stack */
                    conditional_stack_reset(st->cstack);
 
                    /* Read and discard until a sync point in pipeline mode */
                    if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
                    {
                        if (!discardUntilSync(st))
                        {
                            st->state = CSTATE_ABORTED;
                            break;
                        }
                    }
 
                    /*
                     * Check if we have a (failed) transaction block or not,
                     * and roll it back if any.
                     */
                    tstatus = getTransactionStatus(st->con);
                    if (tstatus == TSTATUS_IN_BLOCK)
                    {
                        /* Try to rollback a (failed) transaction block. */
                        if (!PQsendQuery(st->con, "ROLLBACK"))
                        {
                            pg_log_error("client %d aborted: failed to send sql command for rolling back the failed transaction",
                                         st->id);
                            st->state = CSTATE_ABORTED;
                        }
                        else
                            st->state = CSTATE_WAIT_ROLLBACK_RESULT;
                    }
                    else if (tstatus == TSTATUS_IDLE)
                    {
                        /*
                         * If time is over, we're done; otherwise, check if we
                         * can retry the error.
                         */
                        st->state = timer_exceeded ? CSTATE_FINISHED :
                            doRetry(st, &now) ? CSTATE_RETRY : CSTATE_FAILURE;
                    }
                    else
                    {
                        if (tstatus == TSTATUS_CONN_ERROR)
                            pg_log_error("perhaps the backend died while processing");
 
                        pg_log_error("client %d aborted while receiving the transaction status", st->id);
                        st->state = CSTATE_ABORTED;
                    }
                    break;
                }
 
                /*
                 * Wait for the rollback command to complete
                 */
            case CSTATE_WAIT_ROLLBACK_RESULT:
                {
                    PGresult   *res;
 
                    pg_log_debug("client %d receiving", st->id);
                    if (!PQconsumeInput(st->con))
                    {
                        pg_log_error("client %d aborted while rolling back the transaction after an error; perhaps the backend died while processing",
                                     st->id);
                        st->state = CSTATE_ABORTED;
                        break;
                    }
                    if (PQisBusy(st->con))
                        return; /* don't have the whole result yet */
 
                    /*
                     * Read and discard the query result;
                     */
                    res = PQgetResult(st->con);
                    switch (PQresultStatus(res))
                    {
                        case PGRES_COMMAND_OK:
                            /* OK */
                            PQclear(res);
                            /* null must be returned */
                            res = PQgetResult(st->con);
                            Assert(res == NULL);
 
                            /*
                             * If time is over, we're done; otherwise, check
                             * if we can retry the error.
                             */
                            st->state = timer_exceeded ? CSTATE_FINISHED :
                                doRetry(st, &now) ? CSTATE_RETRY : CSTATE_FAILURE;
                            break;
                        default:
                            pg_log_error("client %d aborted while rolling back the transaction after an error; %s",
                                         st->id, PQerrorMessage(st->con));
                            PQclear(res);
                            st->state = CSTATE_ABORTED;
                            break;
                    }
                    break;
                }
 
                /*
                 * Retry the transaction after an error.
                 */
            case CSTATE_RETRY:
                command = sql_script[st->use_file].commands[st->command];
 
                /*
                 * Inform that the transaction will be retried after the
                 * error.
                 */
                if (verbose_errors)
                    printVerboseErrorMessages(st, &now, true);
 
                /* Count tries and retries */
                st->tries++;
                command->retries++;
 
                /*
                 * Reset the random state as they were at the beginning of the
                 * transaction.
                 */
                st->cs_func_rs = st->random_state;
 
                /* Process the first transaction command. */
                st->command = 0;
                st->estatus = ESTATUS_NO_ERROR;
                st->state = CSTATE_START_COMMAND;
                break;
 
                /*
                 * Record a failed transaction.
                 */
            case CSTATE_FAILURE:
                command = sql_script[st->use_file].commands[st->command];
 
                /* Accumulate the failure. */
                command->failures++;
 
                /*
                 * Inform that the failed transaction will not be retried.
                 */
                if (verbose_errors)
                    printVerboseErrorMessages(st, &now, false);
 
                /* End the failed transaction. */
                st->state = CSTATE_END_TX;
                break;
 
                /*
                 * End of transaction (end of script, really).
                 */
            case CSTATE_END_TX:
                {
                    TStatus     tstatus;
 
                    /* transaction finished: calculate latency and do log */
                    processXactStats(thread, st, &now, false, agg);
 
                    /*
                     * missing \endif... cannot happen if CheckConditional was
                     * okay
                     */
                    Assert(conditional_stack_empty(st->cstack));
 
                    /*
                     * We must complete all the transaction blocks that were
                     * started in this script.
                     */
                    tstatus = getTransactionStatus(st->con);
                    if (tstatus == TSTATUS_IN_BLOCK)
                    {
                        pg_log_error("client %d aborted: end of script reached without completing the last transaction",
                                     st->id);
                        st->state = CSTATE_ABORTED;
                        break;
                    }
                    else if (tstatus != TSTATUS_IDLE)
                    {
                        if (tstatus == TSTATUS_CONN_ERROR)
                            pg_log_error("perhaps the backend died while processing");
 
                        pg_log_error("client %d aborted while receiving the transaction status", st->id);
                        st->state = CSTATE_ABORTED;
                        break;
                    }
 
                    if (is_connect)
                    {
                        pg_time_usec_t start = now;
 
                        pg_time_now_lazy(&start);
                        finishCon(st);
                        now = pg_time_now();
                        thread->conn_duration += now - start;
                    }
 
                    if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
                    {
                        /* script completed */
                        st->state = CSTATE_FINISHED;
                        break;
                    }
 
                    /* next transaction (script) */
                    st->state = CSTATE_CHOOSE_SCRIPT;
 
                    /*
                     * Ensure that we always return on this point, so as to
                     * avoid an infinite loop if the script only contains meta
                     * commands.
                     */
                    return;
                }
 
                /*
                 * Final states.  Close the connection if it's still open.
                 */
            case CSTATE_ABORTED:
            case CSTATE_FINISHED:
 
                /*
                 * Don't measure the disconnection delays here even if in
                 * CSTATE_FINISHED and -C/--connect option is specified.
                 * Because in this case all the connections that this thread
                 * established are closed at the end of transactions and the
                 * disconnection delays should have already been measured at
                 * that moment.
                 *
                 * In CSTATE_ABORTED state, the measurement is no longer
                 * necessary because we cannot report complete results anyways
                 * in this case.
                 */
                finishCon(st);
                return;
        }
    }
}
 
/*
 * Subroutine for advanceConnectionState -- initiate or execute the current
 * meta command, and return the next state to set.
 *
 * *now is updated to the current time, unless the command is expected to
 * take no time to execute.
 */
static ConnectionStateEnum
executeMetaCommand(CState *st, pg_time_usec_t *now)
{
    Command    *command = sql_script[st->use_file].commands[st->command];
    int         argc;
    char      **argv;
 
    Assert(command != NULL && command->type == META_COMMAND);
 
    argc = command->argc;
    argv = command->argv;
 
    if (unlikely(__pg_log_level <= PG_LOG_DEBUG))
    {
        PQExpBufferData buf;
 
        initPQExpBuffer(&buf);
 
        printfPQExpBuffer(&buf, "client %d executing \\%s", st->id, argv[0]);
        for (int i = 1; i < argc; i++)
            appendPQExpBuffer(&buf, " %s", argv[i]);
 
        pg_log_debug("%s", buf.data);
 
        termPQExpBuffer(&buf);
    }
 
    if (command->meta == META_SLEEP)
    {
        int         usec;
 
        /*
         * A \sleep doesn't execute anything, we just get the delay from the
         * argument, and enter the CSTATE_SLEEP state.  (The per-command
         * latency will be recorded in CSTATE_SLEEP state, not here, after the
         * delay has elapsed.)
         */
        if (!evaluateSleep(&st->variables, argc, argv, &usec))
        {
            commandFailed(st, "sleep", "execution of meta-command failed");
            return CSTATE_ABORTED;
        }
 
        pg_time_now_lazy(now);
        st->sleep_until = (*now) + usec;
        return CSTATE_SLEEP;
    }
    else if (command->meta == META_SET)
    {
        PgBenchExpr *expr = command->expr;
        PgBenchValue result;
 
        if (!evaluateExpr(st, expr, &result))
        {
            commandFailed(st, argv[0], "evaluation of meta-command failed");
            return CSTATE_ABORTED;
        }
 
        if (!putVariableValue(&st->variables, argv[0], argv[1], &result))
        {
            commandFailed(st, "set", "assignment of meta-command failed");
            return CSTATE_ABORTED;
        }
    }
    else if (command->meta == META_IF)
    {
        /* backslash commands with an expression to evaluate */
        PgBenchExpr *expr = command->expr;
        PgBenchValue result;
        bool        cond;
 
        if (!evaluateExpr(st, expr, &result))
        {
            commandFailed(st, argv[0], "evaluation of meta-command failed");
            return CSTATE_ABORTED;
        }
 
        cond = valueTruth(&result);
        conditional_stack_push(st->cstack, cond ? IFSTATE_TRUE : IFSTATE_FALSE);
    }
    else if (command->meta == META_ELIF)
    {
        /* backslash commands with an expression to evaluate */
        PgBenchExpr *expr = command->expr;
        PgBenchValue result;
        bool        cond;
 
        if (conditional_stack_peek(st->cstack) == IFSTATE_TRUE)
        {
            /* elif after executed block, skip eval and wait for endif. */
            conditional_stack_poke(st->cstack, IFSTATE_IGNORED);
            return CSTATE_END_COMMAND;
        }
 
        if (!evaluateExpr(st, expr, &result))
        {
            commandFailed(st, argv[0], "evaluation of meta-command failed");
            return CSTATE_ABORTED;
        }
 
        cond = valueTruth(&result);
        Assert(conditional_stack_peek(st->cstack) == IFSTATE_FALSE);
        conditional_stack_poke(st->cstack, cond ? IFSTATE_TRUE : IFSTATE_FALSE);
    }
    else if (command->meta == META_ELSE)
    {
        switch (conditional_stack_peek(st->cstack))
        {
            case IFSTATE_TRUE:
                conditional_stack_poke(st->cstack, IFSTATE_ELSE_FALSE);
                break;
            case IFSTATE_FALSE: /* inconsistent if active */
            case IFSTATE_IGNORED:   /* inconsistent if active */
            case IFSTATE_NONE:  /* else without if */
            case IFSTATE_ELSE_TRUE: /* else after else */
            case IFSTATE_ELSE_FALSE:    /* else after else */
            default:
                /* dead code if conditional check is ok */
                Assert(false);
        }
    }
    else if (command->meta == META_ENDIF)
    {
        Assert(!conditional_stack_empty(st->cstack));
        conditional_stack_pop(st->cstack);
    }
    else if (command->meta == META_SETSHELL)
    {
        if (!runShellCommand(&st->variables, argv[1], argv + 2, argc - 2))
        {
            commandFailed(st, "setshell", "execution of meta-command failed");
            return CSTATE_ABORTED;
        }
    }
    else if (command->meta == META_SHELL)
    {
        if (!runShellCommand(&st->variables, NULL, argv + 1, argc - 1))
        {
            commandFailed(st, "shell", "execution of meta-command failed");
            return CSTATE_ABORTED;
        }
    }
    else if (command->meta == META_STARTPIPELINE)
    {
        /*
         * In pipeline mode, we use a workflow based on libpq pipeline
         * functions.
         */
        if (querymode == QUERY_SIMPLE)
        {
            commandFailed(st, "startpipeline", "cannot use pipeline mode with the simple query protocol");
            return CSTATE_ABORTED;
        }
 
        /*
         * If we're in prepared-query mode, we need to prepare all the
         * commands that are inside the pipeline before we actually start the
         * pipeline itself.  This solves the problem that running BEGIN
         * ISOLATION LEVEL SERIALIZABLE in a pipeline would fail due to a
         * snapshot having been acquired by the prepare within the pipeline.
         */
        if (querymode == QUERY_PREPARED)
            prepareCommandsInPipeline(st);
 
        if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
        {
            commandFailed(st, "startpipeline", "already in pipeline mode");
            return CSTATE_ABORTED;
        }
        if (PQenterPipelineMode(st->con) == 0)
        {
            commandFailed(st, "startpipeline", "failed to enter pipeline mode");
            return CSTATE_ABORTED;
        }
    }
    else if (command->meta == META_SYNCPIPELINE)
    {
        if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
        {
            commandFailed(st, "syncpipeline", "not in pipeline mode");
            return CSTATE_ABORTED;
        }
        if (PQsendPipelineSync(st->con) == 0)
        {
            commandFailed(st, "syncpipeline", "failed to send a pipeline sync");
            return CSTATE_ABORTED;
        }
        st->num_syncs++;
    }
    else if (command->meta == META_ENDPIPELINE)
    {
        if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
        {
            commandFailed(st, "endpipeline", "not in pipeline mode");
            return CSTATE_ABORTED;
        }
        if (!PQpipelineSync(st->con))
        {
            commandFailed(st, "endpipeline", "failed to send a pipeline sync");
            return CSTATE_ABORTED;
        }
        st->num_syncs++;
        /* Now wait for the PGRES_PIPELINE_SYNC and exit pipeline mode there */
        /* collect pending results before getting out of pipeline mode */
        return CSTATE_WAIT_RESULT;
    }
 
    /*
     * executing the expression or shell command might have taken a
     * non-negligible amount of time, so reset 'now'
     */
    *now = 0;
 
    return CSTATE_END_COMMAND;
}
 
/*
 * Return the number of failed transactions.
 */
static int64
getFailures(const StatsData *stats)
{
    return (stats->serialization_failures +
            stats->deadlock_failures);
}
 
/*
 * Return a string constant representing the result of a transaction
 * that is not successfully processed.
 */
static const char *
getResultString(bool skipped, EStatus estatus)
{
    if (skipped)
        return "skipped";
    else if (failures_detailed)
    {
        switch (estatus)
        {
            case ESTATUS_SERIALIZATION_ERROR:
                return "serialization";
            case ESTATUS_DEADLOCK_ERROR:
                return "deadlock";
            default:
                /* internal error which should never occur */
                pg_fatal("unexpected error status: %d", estatus);
        }
    }
    else
        return "failed";
}
 
/*
 * Print log entry after completing one transaction.
 *
 * We print Unix-epoch timestamps in the log, so that entries can be
 * correlated against other logs.
 *
 * XXX We could obtain the time from the caller and just shift it here, to
 * avoid the cost of an extra call to pg_time_now().
 */
static void
doLog(TState *thread, CState *st,
      StatsData *agg, bool skipped, double latency, double lag)
{
    FILE       *logfile = thread->logfile;
    pg_time_usec_t now = pg_time_now() + epoch_shift;
 
    Assert(use_log);
 
    /*
     * Skip the log entry if sampling is enabled and this row doesn't belong
     * to the random sample.
     */
    if (sample_rate != 0.0 &&
        pg_prng_double(&thread->ts_sample_rs) > sample_rate)
        return;
 
    /* should we aggregate the results or not? */
    if (agg_interval > 0)
    {
        pg_time_usec_t next;
 
        /*
         * Loop until we reach the interval of the current moment, and print
         * any empty intervals in between (this may happen with very low tps,
         * e.g. --rate=0.1).
         */
 
        while ((next = agg->start_time + agg_interval * INT64CONST(1000000)) <= now)
        {
            double      lag_sum = 0.0;
            double      lag_sum2 = 0.0;
            double      lag_min = 0.0;
            double      lag_max = 0.0;
            int64       skipped = 0;
            int64       serialization_failures = 0;
            int64       deadlock_failures = 0;
            int64       retried = 0;
            int64       retries = 0;
 
            /* print aggregated report to logfile */
            fprintf(logfile, INT64_FORMAT " " INT64_FORMAT " %.0f %.0f %.0f %.0f",
                    agg->start_time / 1000000,  /* seconds since Unix epoch */
                    agg->cnt,
                    agg->latency.sum,
                    agg->latency.sum2,
                    agg->latency.min,
                    agg->latency.max);
 
            if (throttle_delay)
            {
                lag_sum = agg->lag.sum;
                lag_sum2 = agg->lag.sum2;
                lag_min = agg->lag.min;
                lag_max = agg->lag.max;
            }
            fprintf(logfile, " %.0f %.0f %.0f %.0f",
                    lag_sum,
                    lag_sum2,
                    lag_min,
                    lag_max);
 
            if (latency_limit)
                skipped = agg->skipped;
            fprintf(logfile, " " INT64_FORMAT, skipped);
 
            if (max_tries != 1)
            {
                retried = agg->retried;
                retries = agg->retries;
            }
            fprintf(logfile, " " INT64_FORMAT " " INT64_FORMAT, retried, retries);
 
            if (failures_detailed)
            {
                serialization_failures = agg->serialization_failures;
                deadlock_failures = agg->deadlock_failures;
            }
            fprintf(logfile, " " INT64_FORMAT " " INT64_FORMAT,
                    serialization_failures,
                    deadlock_failures);
 
            fputc('\n', logfile);
 
            /* reset data and move to next interval */
            initStats(agg, next);
        }
 
        /* accumulate the current transaction */
        accumStats(agg, skipped, latency, lag, st->estatus, st->tries);
    }
    else
    {
        /* no, print raw transactions */
        if (!skipped && st->estatus == ESTATUS_NO_ERROR)
            fprintf(logfile, "%d " INT64_FORMAT " %.0f %d " INT64_FORMAT " "
                    INT64_FORMAT,
                    st->id, st->cnt, latency, st->use_file,
                    now / 1000000, now % 1000000);
        else
            fprintf(logfile, "%d " INT64_FORMAT " %s %d " INT64_FORMAT " "
                    INT64_FORMAT,
                    st->id, st->cnt, getResultString(skipped, st->estatus),
                    st->use_file, now / 1000000, now % 1000000);
 
        if (throttle_delay)
            fprintf(logfile, " %.0f", lag);
        if (max_tries != 1)
            fprintf(logfile, " %u", st->tries - 1);
        fputc('\n', logfile);
    }
}
 
/*
 * Accumulate and report statistics at end of a transaction.
 *
 * (This is also called when a transaction is late and thus skipped.
 * Note that even skipped and failed transactions are counted in the CState
 * "cnt" field.)
 */
static void
processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
                 bool skipped, StatsData *agg)
{
    double      latency = 0.0,
                lag = 0.0;
    bool        detailed = progress || throttle_delay || latency_limit ||
        use_log || per_script_stats;
 
    if (detailed && !skipped && st->estatus == ESTATUS_NO_ERROR)
    {
        pg_time_now_lazy(now);
 
        /* compute latency & lag */
        latency = (*now) - st->txn_scheduled;
        lag = st->txn_begin - st->txn_scheduled;
    }
 
    /* keep detailed thread stats */
    accumStats(&thread->stats, skipped, latency, lag, st->estatus, st->tries);
 
    /* count transactions over the latency limit, if needed */
    if (latency_limit && latency > latency_limit)
        thread->latency_late++;
 
    /* client stat is just counting */
    st->cnt++;
 
    if (use_log)
        doLog(thread, st, agg, skipped, latency, lag);
 
    /* XXX could use a mutex here, but we choose not to */
    if (per_script_stats)
        accumStats(&sql_script[st->use_file].stats, skipped, latency, lag,
                   st->estatus, st->tries);
}
 
 
/* discard connections */
static void
disconnect_all(CState *state, int length)
{
    int         i;
 
    for (i = 0; i < length; i++)
        finishCon(&state[i]);
}
 
/*
 * Remove old pgbench tables, if any exist
 */
static void
initDropTables(PGconn *con)
{
    fprintf(stderr, "dropping old tables...\n");
 
    /*
     * We drop all the tables in one command, so that whether there are
     * foreign key dependencies or not doesn't matter.
     */
    executeStatement(con, "drop table if exists "
                     "pgbench_accounts, "
                     "pgbench_branches, "
                     "pgbench_history, "
                     "pgbench_tellers");
}
 
/*
 * Create "pgbench_accounts" partitions if needed.
 *
 * This is the larger table of pgbench default tpc-b like schema
 * with a known size, so we choose to partition it.
 */
static void
createPartitions(PGconn *con)
{
    PQExpBufferData query;
 
    /* we must have to create some partitions */
    Assert(partitions > 0);
 
    fprintf(stderr, "creating %d partitions...\n", partitions);
 
    initPQExpBuffer(&query);
 
    for (int p = 1; p <= partitions; p++)
    {
        if (partition_method == PART_RANGE)
        {
            int64       part_size = (naccounts * (int64) scale + partitions - 1) / partitions;
 
            printfPQExpBuffer(&query,
                              "create%s table pgbench_accounts_%d\n"
                              "  partition of pgbench_accounts\n"
                              "  for values from (",
                              unlogged_tables ? " unlogged" : "", p);
 
            /*
             * For RANGE, we use open-ended partitions at the beginning and
             * end to allow any valid value for the primary key.  Although the
             * actual minimum and maximum values can be derived from the
             * scale, it is more generic and the performance is better.
             */
            if (p == 1)
                appendPQExpBufferStr(&query, "minvalue");
            else
                appendPQExpBuffer(&query, INT64_FORMAT, (p - 1) * part_size + 1);
 
            appendPQExpBufferStr(&query, ") to (");
 
            if (p < partitions)
                appendPQExpBuffer(&query, INT64_FORMAT, p * part_size + 1);
            else
                appendPQExpBufferStr(&query, "maxvalue");
 
            appendPQExpBufferChar(&query, ')');
        }
        else if (partition_method == PART_HASH)
            printfPQExpBuffer(&query,
                              "create%s table pgbench_accounts_%d\n"
                              "  partition of pgbench_accounts\n"
                              "  for values with (modulus %d, remainder %d)",
                              unlogged_tables ? " unlogged" : "", p,
                              partitions, p - 1);
        else                    /* cannot get there */
            Assert(0);
 
        /*
         * Per ddlinfo in initCreateTables, fillfactor is needed on table
         * pgbench_accounts.
         */
        appendPQExpBuffer(&query, " with (fillfactor=%d)", fillfactor);
 
        executeStatement(con, query.data);
    }
 
    termPQExpBuffer(&query);
}
 
/*
 * Create pgbench's standard tables
 */
static void
initCreateTables(PGconn *con)
{
    /*
     * Note: TPC-B requires at least 100 bytes per row, and the "filler"
     * fields in these table declarations were intended to comply with that.
     * The pgbench_accounts table complies with that because the "filler"
     * column is set to blank-padded empty string. But for all other tables
     * the columns default to NULL and so don't actually take any space.  We
     * could fix that by giving them non-null default values.  However, that
     * would completely break comparability of pgbench results with prior
     * versions. Since pgbench has never pretended to be fully TPC-B compliant
     * anyway, we stick with the historical behavior.
     */
    struct ddlinfo
    {
        const char *table;      /* table name */
        const char *smcols;     /* column decls if accountIDs are 32 bits */
        const char *bigcols;    /* column decls if accountIDs are 64 bits */
        int         declare_fillfactor;
    };
    static const struct ddlinfo DDLs[] = {
        {
            "pgbench_history",
            "tid int,bid int,aid    int,delta int,mtime timestamp,filler char(22)",
            "tid int,bid int,aid bigint,delta int,mtime timestamp,filler char(22)",
            0
        },
        {
            "pgbench_tellers",
            "tid int not null,bid int,tbalance int,filler char(84)",
            "tid int not null,bid int,tbalance int,filler char(84)",
            1
        },
        {
            "pgbench_accounts",
            "aid    int not null,bid int,abalance int,filler char(84)",
            "aid bigint not null,bid int,abalance int,filler char(84)",
            1
        },
        {
            "pgbench_branches",
            "bid int not null,bbalance int,filler char(88)",
            "bid int not null,bbalance int,filler char(88)",
            1
        }
    };
    int         i;
    PQExpBufferData query;
 
    fprintf(stderr, "creating tables...\n");
 
    initPQExpBuffer(&query);
 
    for (i = 0; i < lengthof(DDLs); i++)
    {
        const struct ddlinfo *ddl = &DDLs[i];
 
        /* Construct new create table statement. */
        printfPQExpBuffer(&query, "create%s table %s(%s)",
                          (unlogged_tables && partition_method == PART_NONE) ? " unlogged" : "",
                          ddl->table,
                          (scale >= SCALE_32BIT_THRESHOLD) ? ddl->bigcols : ddl->smcols);
 
        /* Partition pgbench_accounts table */
        if (partition_method != PART_NONE && strcmp(ddl->table, "pgbench_accounts") == 0)
            appendPQExpBuffer(&query,
                              " partition by %s (aid)", PARTITION_METHOD[partition_method]);
        else if (ddl->declare_fillfactor)
        {
            /* fillfactor is only expected on actual tables */
            appendPQExpBuffer(&query, " with (fillfactor=%d)", fillfactor);
        }
 
        if (tablespace != NULL)
        {
            char       *escape_tablespace;
 
            escape_tablespace = PQescapeIdentifier(con, tablespace, strlen(tablespace));
            appendPQExpBuffer(&query, " tablespace %s", escape_tablespace);
            PQfreemem(escape_tablespace);
        }
 
        executeStatement(con, query.data);
    }
 
    termPQExpBuffer(&query);
 
    if (partition_method != PART_NONE)
        createPartitions(con);
}
 
/*
 * Truncate away any old data, in one command in case there are foreign keys
 */
static void
initTruncateTables(PGconn *con)
{
    executeStatement(con, "truncate table "
                     "pgbench_accounts, "
                     "pgbench_branches, "
                     "pgbench_history, "
                     "pgbench_tellers");
}
 
static void
initBranch(PQExpBufferData *sql, int64 curr)
{
    /* "filler" column uses NULL */
    printfPQExpBuffer(sql,
                      INT64_FORMAT "\t0\t\\N\n",
                      curr + 1);
}
 
static void
initTeller(PQExpBufferData *sql, int64 curr)
{
    /* "filler" column uses NULL */
    printfPQExpBuffer(sql,
                      INT64_FORMAT "\t" INT64_FORMAT "\t0\t\\N\n",
                      curr + 1, curr / ntellers + 1);
}
 
static void
initAccount(PQExpBufferData *sql, int64 curr)
{
    /* "filler" column defaults to blank padded empty string */
    printfPQExpBuffer(sql,
                      INT64_FORMAT "\t" INT64_FORMAT "\t0\t\n",
                      curr + 1, curr / naccounts + 1);
}
 
static void
initPopulateTable(PGconn *con, const char *table, int64 base,
                  initRowMethod init_row)
{
    int         n;
    int64       k;
    int         chars = 0;
    PGresult   *res;
    PQExpBufferData sql;
    char        copy_statement[256];
    const char *copy_statement_fmt = "copy %s from stdin";
    int64       total = base * scale;
 
    /* used to track elapsed time and estimate of the remaining time */
    pg_time_usec_t start;
    int         log_interval = 1;
 
    /* Stay on the same line if reporting to a terminal */
    char        eol = isatty(fileno(stderr)) ? '\r' : '\n';
 
    initPQExpBuffer(&sql);
 
    /*
     * Use COPY with FREEZE on v14 and later for all the tables except
     * pgbench_accounts when it is partitioned.
     */
    if (PQserverVersion(con) >= 140000)
    {
        if (strcmp(table, "pgbench_accounts") != 0 ||
            partitions == 0)
            copy_statement_fmt = "copy %s from stdin with (freeze on)";
    }
 
    n = pg_snprintf(copy_statement, sizeof(copy_statement), copy_statement_fmt, table);
    if (n >= sizeof(copy_statement))
        pg_fatal("invalid buffer size: must be at least %d characters long", n);
    else if (n == -1)
        pg_fatal("invalid format string");
 
    res = PQexec(con, copy_statement);
 
    if (PQresultStatus(res) != PGRES_COPY_IN)
        pg_fatal("unexpected copy in result: %s", PQerrorMessage(con));
    PQclear(res);
 
    start = pg_time_now();
 
    for (k = 0; k < total; k++)
    {
        int64       j = k + 1;
 
        init_row(&sql, k);
        if (PQputline(con, sql.data))
            pg_fatal("PQputline failed");
 
        if (CancelRequested)
            break;
 
        /*
         * If we want to stick with the original logging, print a message each
         * 100k inserted rows.
         */
        if ((!use_quiet) && (j % 100000 == 0))
        {
            double      elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
            double      remaining_sec = ((double) total - j) * elapsed_sec / j;
 
            chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)%c",
                            j, total,
                            (int) ((j * 100) / total),
                            table, elapsed_sec, remaining_sec, eol);
        }
        /* let's not call the timing for each row, but only each 100 rows */
        else if (use_quiet && (j % 100 == 0))
        {
            double      elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
            double      remaining_sec = ((double) total - j) * elapsed_sec / j;
 
            /* have we reached the next interval (or end)? */
            if ((j == total) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
            {
                chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)%c",
                                j, total,
                                (int) ((j * 100) / total),
                                table, elapsed_sec, remaining_sec, eol);
 
                /* skip to the next interval */
                log_interval = (int) ceil(elapsed_sec / LOG_STEP_SECONDS);
            }
        }
    }
 
    if (chars != 0 && eol != '\n')
        fprintf(stderr, "%*c\r", chars - 1, ' ');   /* Clear the current line */
 
    if (PQputline(con, "\\.\n"))
        pg_fatal("very last PQputline failed");
    if (PQendcopy(con))
        pg_fatal("PQendcopy failed");
 
    termPQExpBuffer(&sql);
}
 
/*
 * Fill the standard tables with some data generated and sent from the client.
 *
 * The filler column is NULL in pgbench_branches and pgbench_tellers, and is
 * a blank-padded string in pgbench_accounts.
 */
static void
initGenerateDataClientSide(PGconn *con)
{
    fprintf(stderr, "generating data (client-side)...\n");
 
    /*
     * we do all of this in one transaction to enable the backend's
     * data-loading optimizations
     */
    executeStatement(con, "begin");
 
    /* truncate away any old data */
    initTruncateTables(con);
 
    /*
     * fill branches, tellers, accounts in that order in case foreign keys
     * already exist
     */
    initPopulateTable(con, "pgbench_branches", nbranches, initBranch);
    initPopulateTable(con, "pgbench_tellers", ntellers, initTeller);
    initPopulateTable(con, "pgbench_accounts", naccounts, initAccount);
 
    executeStatement(con, "commit");
}
 
/*
 * Fill the standard tables with some data generated on the server
 *
 * As already the case with the client-side data generation, the filler
 * column defaults to NULL in pgbench_branches and pgbench_tellers,
 * and is a blank-padded string in pgbench_accounts.
 */
static void
initGenerateDataServerSide(PGconn *con)
{
    PQExpBufferData sql;
 
    fprintf(stderr, "generating data (server-side)...\n");
 
    /*
     * we do all of this in one transaction to enable the backend's
     * data-loading optimizations
     */
    executeStatement(con, "begin");
 
    /* truncate away any old data */
    initTruncateTables(con);
 
    initPQExpBuffer(&sql);
 
    printfPQExpBuffer(&sql,
                      "insert into pgbench_branches(bid,bbalance) "
                      "select bid, 0 "
                      "from generate_series(1, %d) as bid", nbranches * scale);
    executeStatement(con, sql.data);
 
    printfPQExpBuffer(&sql,
                      "insert into pgbench_tellers(tid,bid,tbalance) "
                      "select tid, (tid - 1) / %d + 1, 0 "
                      "from generate_series(1, %d) as tid", ntellers, ntellers * scale);
    executeStatement(con, sql.data);
 
    printfPQExpBuffer(&sql,
                      "insert into pgbench_accounts(aid,bid,abalance,filler) "
                      "select aid, (aid - 1) / %d + 1, 0, '' "
                      "from generate_series(1, " INT64_FORMAT ") as aid",
                      naccounts, (int64) naccounts * scale);
    executeStatement(con, sql.data);
 
    termPQExpBuffer(&sql);
 
    executeStatement(con, "commit");
}
 
/*
 * Invoke vacuum on the standard tables
 */
static void
initVacuum(PGconn *con)
{
    fprintf(stderr, "vacuuming...\n");
    executeStatement(con, "vacuum analyze pgbench_branches");
    executeStatement(con, "vacuum analyze pgbench_tellers");
    executeStatement(con, "vacuum analyze pgbench_accounts");
    executeStatement(con, "vacuum analyze pgbench_history");
}
 
/*
 * Create primary keys on the standard tables
 */
static void
initCreatePKeys(PGconn *con)
{
    static const char *const DDLINDEXes[] = {
        "alter table pgbench_branches add primary key (bid)",
        "alter table pgbench_tellers add primary key (tid)",
        "alter table pgbench_accounts add primary key (aid)"
    };
    int         i;
    PQExpBufferData query;
 
    fprintf(stderr, "creating primary keys...\n");
    initPQExpBuffer(&query);
 
    for (i = 0; i < lengthof(DDLINDEXes); i++)
    {
        resetPQExpBuffer(&query);
        appendPQExpBufferStr(&query, DDLINDEXes[i]);
 
        if (index_tablespace != NULL)
        {
            char       *escape_tablespace;
 
            escape_tablespace = PQescapeIdentifier(con, index_tablespace,
                                                   strlen(index_tablespace));
            appendPQExpBuffer(&query, " using index tablespace %s", escape_tablespace);
            PQfreemem(escape_tablespace);
        }
 
        executeStatement(con, query.data);
    }
 
    termPQExpBuffer(&query);
}
 
/*
 * Create foreign key constraints between the standard tables
 */
static void
initCreateFKeys(PGconn *con)
{
    static const char *const DDLKEYs[] = {
        "alter table pgbench_tellers add constraint pgbench_tellers_bid_fkey foreign key (bid) references pgbench_branches",
        "alter table pgbench_accounts add constraint pgbench_accounts_bid_fkey foreign key (bid) references pgbench_branches",
        "alter table pgbench_history add constraint pgbench_history_bid_fkey foreign key (bid) references pgbench_branches",
        "alter table pgbench_history add constraint pgbench_history_tid_fkey foreign key (tid) references pgbench_tellers",
        "alter table pgbench_history add constraint pgbench_history_aid_fkey foreign key (aid) references pgbench_accounts"
    };
    int         i;
 
    fprintf(stderr, "creating foreign keys...\n");
    for (i = 0; i < lengthof(DDLKEYs); i++)
    {
        executeStatement(con, DDLKEYs[i]);
    }
}
 
/*
 * Validate an initialization-steps string
 *
 * (We could just leave it to runInitSteps() to fail if there are wrong
 * characters, but since initialization can take awhile, it seems friendlier
 * to check during option parsing.)
 */
static void
checkInitSteps(const char *initialize_steps)
{
    if (initialize_steps[0] == '\0')
        pg_fatal("no initialization steps specified");
 
    for (const char *step = initialize_steps; *step != '\0'; step++)
    {
        if (strchr(ALL_INIT_STEPS " ", *step) == NULL)
        {
            pg_log_error("unrecognized initialization step \"%c\"", *step);
            pg_log_error_detail("Allowed step characters are: \"" ALL_INIT_STEPS "\".");
            exit(1);
        }
    }
}
 
/*
 * Invoke each initialization step in the given string
 */
static void
runInitSteps(const char *initialize_steps)
{
    PQExpBufferData stats;
    PGconn     *con;
    const char *step;
    double      run_time = 0.0;
    bool        first = true;
 
    initPQExpBuffer(&stats);
 
    if ((con = doConnect()) == NULL)
        pg_fatal("could not create connection for initialization");
 
    setup_cancel_handler(NULL);
    SetCancelConn(con);
 
    for (step = initialize_steps; *step != '\0'; step++)
    {
        char       *op = NULL;
        pg_time_usec_t start = pg_time_now();
 
        switch (*step)
        {
            case 'd':
                op = "drop tables";
                initDropTables(con);
                break;
            case 't':
                op = "create tables";
                initCreateTables(con);
                break;
            case 'g':
                op = "client-side generate";
                initGenerateDataClientSide(con);
                break;
            case 'G':
                op = "server-side generate";
                initGenerateDataServerSide(con);
                break;
            case 'v':
                op = "vacuum";
                initVacuum(con);
                break;
            case 'p':
                op = "primary keys";
                initCreatePKeys(con);
                break;
            case 'f':
                op = "foreign keys";
                initCreateFKeys(con);
                break;
            case ' ':
                break;          /* ignore */
            default:
                pg_log_error("unrecognized initialization step \"%c\"", *step);
                PQfinish(con);
                exit(1);
        }
 
        if (op != NULL)
        {
            double      elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
 
            if (!first)
                appendPQExpBufferStr(&stats, ", ");
            else
                first = false;
 
            appendPQExpBuffer(&stats, "%s %.2f s", op, elapsed_sec);
 
            run_time += elapsed_sec;
        }
    }
 
    fprintf(stderr, "done in %.2f s (%s).\n", run_time, stats.data);
    ResetCancelConn();
    PQfinish(con);
    termPQExpBuffer(&stats);
}
 
/*
 * Extract pgbench table information into global variables scale,
 * partition_method and partitions.
 */
static void
GetTableInfo(PGconn *con, bool scale_given)
{
    PGresult   *res;
 
    /*
     * get the scaling factor that should be same as count(*) from
     * pgbench_branches if this is not a custom query
     */
    res = PQexec(con, "select count(*) from pgbench_branches");
    if (PQresultStatus(res) != PGRES_TUPLES_OK)
    {
        char       *sqlState = PQresultErrorField(res, PG_DIAG_SQLSTATE);
 
        pg_log_error("could not count number of branches: %s", PQerrorMessage(con));
 
        if (sqlState && strcmp(sqlState, ERRCODE_UNDEFINED_TABLE) == 0)
            pg_log_error_hint("Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\".",
                              PQdb(con));
 
        exit(1);
    }
    scale = atoi(PQgetvalue(res, 0, 0));
    if (scale < 0)
        pg_fatal("invalid count(*) from pgbench_branches: \"%s\"",
                 PQgetvalue(res, 0, 0));
    PQclear(res);
 
    /* warn if we override user-given -s switch */
    if (scale_given)
        pg_log_warning("scale option ignored, using count from pgbench_branches table (%d)",
                       scale);
 
    /*
     * Get the partition information for the first "pgbench_accounts" table
     * found in search_path.
     *
     * The result is empty if no "pgbench_accounts" is found.
     *
     * Otherwise, it always returns one row even if the table is not
     * partitioned (in which case the partition strategy is NULL).
     *
     * The number of partitions can be 0 even for partitioned tables, if no
     * partition is attached.
     *
     * We assume no partitioning on any failure, so as to avoid failing on an
     * old version without "pg_partitioned_table".
     */
    res = PQexec(con,
                 "select o.n, p.partstrat, pg_catalog.count(i.inhparent) "
                 "from pg_catalog.pg_class as c "
                 "join pg_catalog.pg_namespace as n on (n.oid = c.relnamespace) "
                 "cross join lateral (select pg_catalog.array_position(pg_catalog.current_schemas(true), n.nspname)) as o(n) "
                 "left join pg_catalog.pg_partitioned_table as p on (p.partrelid = c.oid) "
                 "left join pg_catalog.pg_inherits as i on (c.oid = i.inhparent) "
                 "where c.relname = 'pgbench_accounts' and o.n is not null "
                 "group by 1, 2 "
                 "order by 1 asc "
                 "limit 1");
 
    if (PQresultStatus(res) != PGRES_TUPLES_OK)
    {
        /* probably an older version, coldly assume no partitioning */
        partition_method = PART_NONE;
        partitions = 0;
    }
    else if (PQntuples(res) == 0)
    {
        /*
         * This case is unlikely as pgbench already found "pgbench_branches"
         * above to compute the scale.
         */
        pg_log_error("no pgbench_accounts table found in \"search_path\"");
        pg_log_error_hint("Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\".", PQdb(con));
        exit(1);
    }
    else                        /* PQntuples(res) == 1 */
    {
        /* normal case, extract partition information */
        if (PQgetisnull(res, 0, 1))
            partition_method = PART_NONE;
        else
        {
            char       *ps = PQgetvalue(res, 0, 1);
 
            /* column must be there */
            Assert(ps != NULL);
 
            if (strcmp(ps, "r") == 0)
                partition_method = PART_RANGE;
            else if (strcmp(ps, "h") == 0)
                partition_method = PART_HASH;
            else
            {
                /* possibly a newer version with new partition method */
                pg_fatal("unexpected partition method: \"%s\"", ps);
            }
        }
 
        partitions = atoi(PQgetvalue(res, 0, 2));
    }
 
    PQclear(res);
}
 
/*
 * Replace :param with $n throughout the command's SQL text, which
 * is a modifiable string in cmd->lines.
 */
static bool
parseQuery(Command *cmd)
{
    char       *sql,
               *p;
 
    cmd->argc = 1;
 
    p = sql = pg_strdup(cmd->lines.data);
    while ((p = strchr(p, ':')) != NULL)
    {
        char        var[13];
        char       *name;
        int         eaten;
 
        name = parseVariable(p, &eaten);
        if (name == NULL)
        {
            while (*p == ':')
            {
                p++;
            }
            continue;
        }
 
        /*
         * cmd->argv[0] is the SQL statement itself, so the max number of
         * arguments is one less than MAX_ARGS
         */
        if (cmd->argc >= MAX_ARGS)
        {
            pg_log_error("statement has too many arguments (maximum is %d): %s",
                         MAX_ARGS - 1, cmd->lines.data);
            pg_free(name);
            return false;
        }
 
        sprintf(var, "$%d", cmd->argc);
        p = replaceVariable(&sql, p, eaten, var);
 
        cmd->argv[cmd->argc] = name;
        cmd->argc++;
    }
 
    Assert(cmd->argv[0] == NULL);
    cmd->argv[0] = sql;
    return true;
}
 
/*
 * syntax error while parsing a script (in practice, while parsing a
 * backslash command, because we don't detect syntax errors in SQL)
 *
 * source: source of script (filename or builtin-script ID)
 * lineno: line number within script (count from 1)
 * line: whole line of backslash command, if available
 * command: backslash command name, if available
 * msg: the actual error message
 * more: optional extra message
 * column: zero-based column number, or -1 if unknown
 */
void
syntax_error(const char *source, int lineno,
             const char *line, const char *command,
             const char *msg, const char *more, int column)
{
    PQExpBufferData buf;
 
    initPQExpBuffer(&buf);
 
    printfPQExpBuffer(&buf, "%s:%d: %s", source, lineno, msg);
    if (more != NULL)
        appendPQExpBuffer(&buf, " (%s)", more);
    if (column >= 0 && line == NULL)
        appendPQExpBuffer(&buf, " at column %d", column + 1);
    if (command != NULL)
        appendPQExpBuffer(&buf, " in command \"%s\"", command);
 
    pg_log_error("%s", buf.data);
 
    termPQExpBuffer(&buf);
 
    if (line != NULL)
    {
        fprintf(stderr, "%s\n", line);
        if (column >= 0)
            fprintf(stderr, "%*c error found here\n", column + 1, '^');
    }
 
    exit(1);
}
 
/*
 * Return a pointer to the start of the SQL command, after skipping over
 * whitespace and "--" comments.
 * If the end of the string is reached, return NULL.
 */
static char *
skip_sql_comments(char *sql_command)
{
    char       *p = sql_command;
 
    /* Skip any leading whitespace, as well as "--" style comments */
    for (;;)
    {
        if</