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) 2000-2017, 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.
 *
 */

#ifdef WIN32
#define FD_SETSIZE 1024         /* set before winsock2.h is included */
#endif                          /* ! WIN32 */

#include "postgres_fe.h"

#include "getopt_long.h"
#include "libpq-fe.h"
#include "portability/instr_time.h"

#include <ctype.h>
#include <float.h>
#include <limits.h>
#include <math.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>       /* for getrlimit */
#endif

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#include "pgbench.h"

#define ERRCODE_UNDEFINED_TABLE  "42P01"

/*
 * Multi-platform pthread implementations
 */

#ifdef WIN32
/* Use native win32 threads on Windows */
typedef struct win32_pthread *pthread_t;
typedef int pthread_attr_t;

static int  pthread_create(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);
static int  pthread_join(pthread_t th, void **thread_return);
#elif defined(ENABLE_THREAD_SAFETY)
/* Use platform-dependent pthread capability */
#include <pthread.h>
#else
/* No threads implementation, use none (-j 1) */
#define pthread_t void *
#endif


/********************************************************************
 * some configurable parameters */

/* max number of clients allowed */
#ifdef FD_SETSIZE
#define MAXCLIENTS  (FD_SETSIZE - 10)
#else
#define MAXCLIENTS  1024
#endif

#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 */

int         nxacts = 0;         /* number of transactions per client */
int         duration = 0;       /* duration in seconds */
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.
 */
int         scale = 1;

/*
 * fillfactor. for example, fillfactor = 90 will use only 90 percent
 * space during inserts and leave 10 percent free.
 */
int         fillfactor = 100;

/*
 * create foreign key constraints on the tables?
 */
int         foreign_keys = 0;

/*
 * use unlogged tables?
 */
int         unlogged_tables = 0;

/*
 * log sampling rate (1.0 = log everything, 0.0 = option not given)
 */
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.
 */
int64       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.
 */
int64       latency_limit = 0;

/*
 * tablespace selection
 */
char       *tablespace = NULL;
char       *index_tablespace = NULL;

/*
 * 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

bool        use_log;            /* log transaction latencies to a file */
bool        use_quiet;          /* quiet logging onto stderr */
int         agg_interval;       /* log aggregates instead of individual
                                 * transactions */
bool        per_script_stats = false;   /* whether to collect stats per script */
int         progress = 0;       /* thread progress report every this seconds */
bool        progress_timestamp = false; /* progress report with Unix time */
int         nclients = 1;       /* number of clients */
int         nthreads = 1;       /* number of threads */
bool        is_connect;         /* establish connection for each transaction */
bool        is_latencies;       /* report per-command latencies */
int         main_pid;           /* main process id used in log filename */

char       *pghost = "";
char       *pgport = "";
char       *login = NULL;
char       *dbName;
char       *logfile_prefix = NULL;
const char *progname;

#define WSEP '@'                /* weight separator */

volatile bool timer_exceeded = false;   /* flag from signal handler */

/*
 * Variable definitions.  If a variable has a string value, "value" is that
 * value, is_numeric is false, and num_value is undefined.  If the value is
 * known to be numeric, is_numeric is true and num_value contains the value
 * (in any permitted numeric variant).  In this case "value" contains the
 * string equivalent of the number, if we've had occasion to compute that,
 * or NULL if we haven't.
 */
typedef struct
{
    char       *name;           /* variable's name */
    char       *value;          /* its value in string form, if known */
    bool        is_numeric;     /* is numeric value known? */
    PgBenchValue num_value;     /* variable's value in numeric form */
} Variable;

#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;

/*
 * Data structure to hold various statistics: per-thread and per-script stats
 * are maintained and merged together.
 */
typedef struct StatsData
{
    time_t      start_time;     /* interval start time, for aggregates */
    int64       cnt;            /* number of transactions, including skipped */
    int64       skipped;        /* number of transactions skipped under --rate
                                 * and --latency-limit */
    SimpleStats latency;
    SimpleStats lag;
} StatsData;

/*
 * Connection state machine states.
 */
typedef enum
{
    /*
     * The client must first choose a script to execute.  Once chosen, it can
     * either be throttled (state CSTATE_START_THROTTLE under --rate) or start
     * right away (state CSTATE_START_TX).
     */
    CSTATE_CHOOSE_SCRIPT,

    /*
     * In CSTATE_START_THROTTLE state, we calculate when to begin the next
     * transaction, and advance to CSTATE_THROTTLE.  CSTATE_THROTTLE state
     * sleeps until that moment.  (If throttling is not enabled, doCustom()
     * falls directly through from CSTATE_START_THROTTLE to CSTATE_START_TX.)
     */
    CSTATE_START_THROTTLE,
    CSTATE_THROTTLE,

    /*
     * CSTATE_START_TX performs start-of-transaction processing.  Establishes
     * a new connection for the transaction, in --connect mode, and records
     * the transaction start time.
     */
    CSTATE_START_TX,

    /*
     * 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.  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.
     *
     * 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_START_COMMAND,
    CSTATE_WAIT_RESULT,
    CSTATE_SLEEP,
    CSTATE_END_COMMAND,

    /*
     * CSTATE_END_TX performs end-of-transaction processing.  Calculates
     * latency, and logs the transaction.  In --connect mode, closes the
     * current connection.  Chooses the next script to execute and starts over
     * in CSTATE_START_THROTTLE state, 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. */

    int         use_file;       /* index in sql_script for this client */
    int         command;        /* command number in script */

    /* client variables */
    Variable   *variables;      /* array of variable definitions */
    int         nvariables;     /* number of variables */
    bool        vars_sorted;    /* are variables sorted by name? */

    /* various times about current transaction */
    int64       txn_scheduled;  /* scheduled start time of transaction (usec) */
    int64       sleep_until;    /* scheduled start time of next cmd (usec) */
    instr_time  txn_begin;      /* used for measuring schedule lag times */
    instr_time  stmt_begin;     /* used for measuring statement latencies */

    bool        prepared[MAX_SCRIPTS];  /* whether client prepared the script */

    /* per client collected stats */
    int64       cnt;            /* client transaction count, for -t */
    int         ecnt;           /* error count */
} CState;

/*
 * Thread state
 */
typedef struct
{
    int         tid;            /* thread id */
    pthread_t   thread;         /* thread handle */
    CState     *state;          /* array of CState */
    int         nstate;         /* length of state[] */
    unsigned short random_state[3]; /* separate randomness for each thread */
    int64       throttle_trigger;   /* previous/next throttling (us) */
    FILE       *logfile;        /* where to log, or NULL */

    /* per thread collected stats */
    instr_time  start_time;     /* thread start time */
    instr_time  conn_time;
    StatsData   stats;
    int64       latency_late;   /* executed but late transactions */
} TState;

#define INVALID_THREAD      ((pthread_t) 0)

/*
 * queries read from files
 */
#define SQL_COMMAND     1
#define META_COMMAND    2
#define MAX_ARGS        10

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 *QUERYMODE[] = {"simple", "extended", "prepared"};

typedef struct
{
    char       *line;           /* text of command line */
    int         command_num;    /* unique index of this Command struct */
    int         type;           /* command type (SQL_COMMAND or META_COMMAND) */
    int         argc;           /* number of command words */
    char       *argv[MAX_ARGS]; /* command word list */
    PgBenchExpr *expr;          /* parsed expression, if needed */
    SimpleStats stats;          /* time spent in this command */
} 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 int  num_commands = 0;   /* total number of Command structs */
static int64 total_weight = 0;

static int  debug = 0;          /* debug flag */

/* 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 setIntValue(PgBenchValue *pv, int64 ival);
static void setDoubleValue(PgBenchValue *pv, double dval);
static bool evaluateExpr(TState *, CState *, PgBenchExpr *, PgBenchValue *);
static void doLog(TState *thread, CState *st,
      StatsData *agg, bool skipped, double latency, double lag);
static void processXactStats(TState *thread, CState *st, instr_time *now,
                 bool skipped, StatsData *agg);
static void pgbench_error(const char *fmt,...) pg_attribute_printf(1, 2);
static void addScript(ParsedScript script);
static void *threadRun(void *arg);
static void setalarm(int seconds);


/* callback functions for our flex lexer */
static const PsqlScanCallbacks pgbench_callbacks = {
    NULL,                       /* don't need get_variable functionality */
    pgbench_error
};


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"
           "  -F, --fillfactor=NUM     set fill factor\n"
           "  -n, --no-vacuum          do not run VACUUM after 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"
           "  --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-latencies   report average latency 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"
           "  --log-prefix=PREFIX      prefix for transaction time log file\n"
           "                           (default: \"pgbench_log\")\n"
           "  --progress-timestamp     use Unix epoch timestamps for progress\n"
           "  --sampling-rate=NUM      fraction of transactions to log (e.g., 0.01 for 1%%)\n"
           "\nCommon options:\n"
           "  -d, --debug              print debugging output\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 <pgsql-bugs@postgresql.org>.\n",
           progname, progname);
}

/* 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 modified version of scanint8() from
 * src/backend/utils/adt/int8.c.
 */
int64
strtoint64(const char *str)
{
    const char *ptr = str;
    int64       result = 0;
    int         sign = 1;

    /*
     * Do our own scan, rather than relying on sscanf which might be broken
     * for long long.
     */

    /* skip leading spaces */
    while (*ptr && isspace((unsigned char) *ptr))
        ptr++;

    /* handle sign */
    if (*ptr == '-')
    {
        ptr++;

        /*
         * Do an explicit check for INT64_MIN.  Ugly though this is, it's
         * cleaner than trying to get the loop below to handle it portably.
         */
        if (strncmp(ptr, "9223372036854775808", 19) == 0)
        {
            result = PG_INT64_MIN;
            ptr += 19;
            goto gotdigits;
        }
        sign = -1;
    }
    else if (*ptr == '+')
        ptr++;

    /* require at least one digit */
    if (!isdigit((unsigned char) *ptr))
        fprintf(stderr, "invalid input syntax for integer: \"%s\"\n", str);

    /* process digits */
    while (*ptr && isdigit((unsigned char) *ptr))
    {
        int64       tmp = result * 10 + (*ptr++ - '0');

        if ((tmp / 10) != result)   /* overflow? */
            fprintf(stderr, "value \"%s\" is out of range for type bigint\n", str);
        result = tmp;
    }

gotdigits:

    /* allow trailing whitespace, but not other trailing chars */
    while (*ptr != '\0' && isspace((unsigned char) *ptr))
        ptr++;

    if (*ptr != '\0')
        fprintf(stderr, "invalid input syntax for integer: \"%s\"\n", str);

    return ((sign < 0) ? -result : result);
}

/* random number generator: uniform distribution from min to max inclusive */
static int64
getrand(TState *thread, int64 min, int64 max)
{
    /*
     * Odd coding is so that min and max have approximately the same chance of
     * being selected as do numbers between them.
     *
     * pg_erand48() is thread-safe and concurrent, which is why we use it
     * rather than random(), which in glibc is non-reentrant, and therefore
     * protected by a mutex, and therefore a bottleneck on machines with many
     * CPUs.
     */
    return min + (int64) ((max - min + 1) * pg_erand48(thread->random_state));
}

/*
 * 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(TState *thread, 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);
    /* erand in [0, 1), uniform in (0, 1] */
    uniform = 1.0 - pg_erand48(thread->random_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(TState *thread, 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 user specified random number from this loop, with -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
    {
        /*
         * pg_erand48 generates [0,1), but for the basic version of the
         * Box-Muller transform the two uniformly distributed random numbers
         * are expected in (0, 1] (see
         * http://en.wikipedia.org/wiki/Box_muller)
         */
        double      rand1 = 1.0 - pg_erand48(thread->random_state);
        double      rand2 = 1.0 - pg_erand48(thread->random_state);

        /* Box-Muller basic form transform */
        double      var_sqrt = sqrt(-2.0 * log(rand1));

        stdev = var_sqrt * sin(2.0 * M_PI * rand2);

        /*
         * we may try with cos, but there may be a bias induced if the
         * previous value fails the test. To be on the safe side, let us try
         * over.
         */
    }
    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.
 */
static int64
getPoissonRand(TState *thread, int64 center)
{
    /*
     * Use inverse transform sampling to generate a value > 0, such that the
     * expected (i.e. average) value is the given argument.
     */
    double      uniform;

    /* erand in [0, 1), uniform in (0, 1] */
    uniform = 1.0 - pg_erand48(thread->random_state);

    return (int64) (-log(uniform) * ((double) center) + 0.5);
}

/*
 * 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, time_t start_time)
{
    sd->start_time = start_time;
    sd->cnt = 0;
    sd->skipped = 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)
{
    stats->cnt++;

    if (skipped)
    {
        /* no latency to record on skipped transactions */
        stats->skipped++;
    }
    else
    {
        addToSimpleStats(&stats->latency, lat);

        /* and possibly the same for schedule lag */
        if (throttle_delay)
            addToSimpleStats(&stats->lag, lag);
    }
}

/* 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)
    {
        fprintf(stderr, "%s", PQerrorMessage(con));
        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)
    {
        fprintf(stderr, "%s", PQerrorMessage(con));
        fprintf(stderr, "(ignoring this error and continuing anyway)\n");
    }
    PQclear(res);
}

/* set up a connection to the backend */
static PGconn *
doConnect(void)
{
    PGconn     *conn;
    bool        new_pass;
    static bool have_password = false;
    static char password[100];

    /*
     * 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] = login;
        keywords[3] = "password";
        values[3] = have_password ? password : NULL;
        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)
        {
            fprintf(stderr, "connection to database \"%s\" failed\n",
                    dbName);
            return NULL;
        }

        if (PQstatus(conn) == CONNECTION_BAD &&
            PQconnectionNeedsPassword(conn) &&
            !have_password)
        {
            PQfinish(conn);
            simple_prompt("Password: ", password, sizeof(password), false);
            have_password = true;
            new_pass = true;
        }
    } while (new_pass);

    /* check to see that the backend connection was successfully made */
    if (PQstatus(conn) == CONNECTION_BAD)
    {
        fprintf(stderr, "connection to database \"%s\" failed:\n%s",
                dbName, PQerrorMessage(conn));
        PQfinish(conn);
        return NULL;
    }

    return conn;
}

/* throw away response from backend */
static void
discard_response(CState *state)
{
    PGresult   *res;

    do
    {
        res = PQgetResult(state->con);
        if (res)
            PQclear(res);
    } while (res);
}

/* 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(CState *st, char *name)
{
    Variable    key;

    /* On some versions of Solaris, bsearch of zero items dumps core */
    if (st->nvariables <= 0)
        return NULL;

    /* Sort if we have to */
    if (!st->vars_sorted)
    {
        qsort((void *) st->variables, st->nvariables, sizeof(Variable),
              compareVariableNames);
        st->vars_sorted = true;
    }

    /* Now we can search */
    key.name = name;
    return (Variable *) bsearch((void *) &key,
                                (void *) st->variables,
                                st->nvariables,
                                sizeof(Variable),
                                compareVariableNames);
}

/* Get the value of a variable, in string form; returns NULL if unknown */
static char *
getVariable(CState *st, char *name)
{
    Variable   *var;
    char        stringform[64];

    var = lookupVariable(st, name);
    if (var == NULL)
        return NULL;            /* not found */

    if (var->value)
        return var->value;      /* we have it in string form */

    /* We need to produce a string equivalent of the numeric value */
    Assert(var->is_numeric);
    if (var->num_value.type == PGBT_INT)
        snprintf(stringform, sizeof(stringform),
                 INT64_FORMAT, var->num_value.u.ival);
    else
    {
        Assert(var->num_value.type == PGBT_DOUBLE);
        snprintf(stringform, sizeof(stringform),
                 "%.*g", DBL_DIG, var->num_value.u.dval);
    }
    var->value = pg_strdup(stringform);
    return var->value;
}

/* Try to convert variable to numeric form; return false on failure */
static bool
makeVariableNumeric(Variable *var)
{
    if (var->is_numeric)
        return true;            /* no work */

    if (is_an_int(var->value))
    {
        setIntValue(&var->num_value, strtoint64(var->value));
        var->is_numeric = true;
    }
    else                        /* type should be double */
    {
        double      dv;
        char        xs;

        if (sscanf(var->value, "%lf%c", &dv, &xs) != 1)
        {
            fprintf(stderr,
                    "malformed variable \"%s\" value: \"%s\"\n",
                    var->name, var->value);
            return false;
        }
        setDoubleValue(&var->num_value, dv);
        var->is_numeric = true;
    }
    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"
 */
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;

    while (*ptr)
    {
        if (IS_HIGHBIT_SET(*ptr) ||
            strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                   "_0123456789", *ptr) != NULL)
            ptr++;
        else
            return false;
    }

    return true;
}

/*
 * 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(CState *st, const char *context, char *name)
{
    Variable   *var;

    var = lookupVariable(st, name);
    if (var == NULL)
    {
        Variable   *newvars;

        /*
         * Check for the name only when declaring a new variable to avoid
         * overhead.
         */
        if (!valid_variable_name(name))
        {
            fprintf(stderr, "%s: invalid variable name: \"%s\"\n",
                    context, name);
            return NULL;
        }

        /* Create variable at the end of the array */
        if (st->variables)
            newvars = (Variable *) pg_realloc(st->variables,
                                              (st->nvariables + 1) * sizeof(Variable));
        else
            newvars = (Variable *) pg_malloc(sizeof(Variable));

        st->variables = newvars;

        var = &newvars[st->nvariables];

        var->name = pg_strdup(name);
        var->value = NULL;
        /* caller is expected to initialize remaining fields */

        st->nvariables++;
        /* we don't re-sort the array till we have to */
        st->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(CState *st, const char *context, char *name, const char *value)
{
    Variable   *var;
    char       *val;

    var = lookupCreateVariable(st, context, name);
    if (!var)
        return false;

    /* dup then free, in case value is pointing at this variable */
    val = pg_strdup(value);

    if (var->value)
        free(var->value);
    var->value = val;
    var->is_numeric = false;

    return true;
}

/* Assign a numeric value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariableNumber(CState *st, const char *context, char *name,
                  const PgBenchValue *value)
{
    Variable   *var;

    var = lookupCreateVariable(st, context, name);
    if (!var)
        return false;

    if (var->value)
        free(var->value);
    var->value = NULL;
    var->is_numeric = true;
    var->num_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(CState *st, const char *context, char *name, int64 value)
{
    PgBenchValue val;

    setIntValue(&val, value);
    return putVariableNumber(st, 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.
 * Otherwise, return NULL.
 */
static char *
parseVariable(const char *sql, int *eaten)
{
    int         i = 0;
    char       *name;

    do
    {
        i++;
    } while (IS_HIGHBIT_SET(sql[i]) ||
             strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                    "_0123456789", sql[i]) != NULL);
    if (i == 1)
        return NULL;            /* no valid variable name chars */

    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(CState *st, 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(st, name);
        free(name);
        if (val == NULL)
        {
            p++;
            continue;
        }

        p = replaceVariable(&sql, p, eaten, val);
    }

    return sql;
}

static void
getQueryParams(CState *st, const Command *command, const char **params)
{
    int         i;

    for (i = 0; i < command->argc - 1; i++)
        params[i] = getVariable(st, command->argv[i + 1]);
}

/* 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
    {
        double      dval = pval->u.dval;

        Assert(pval->type == PGBT_DOUBLE);
        if (dval < PG_INT64_MIN || PG_INT64_MAX < dval)
        {
            fprintf(stderr, "double to int overflow for %f\n", dval);
            return false;
        }
        *ival = (int64) dval;
        return true;
    }
}

/* 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
    {
        Assert(pval->type == PGBT_INT);
        *dval = (double) pval->u.ival;
        return true;
    }
}

/* 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;
}

/* maximum number of function arguments */
#define MAX_FARGS 16

/*
 * Recursive evaluation of functions
 */
static bool
evalFunc(TState *thread, CState *st,
         PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
{
    /* evaluate all function arguments */
    int         nargs = 0;
    PgBenchValue vargs[MAX_FARGS];
    PgBenchExprLink *l = args;

    for (nargs = 0; nargs < MAX_FARGS && l != NULL; nargs++, l = l->next)
        if (!evaluateExpr(thread, st, l->expr, &vargs[nargs]))
            return false;

    if (l != NULL)
    {
        fprintf(stderr,
                "too many function arguments, maximum is %d\n", MAX_FARGS);
        return false;
    }

    /* then evaluate function */
    switch (func)
    {
            /* overloaded operators */
        case PGBENCH_ADD:
        case PGBENCH_SUB:
        case PGBENCH_MUL:
        case PGBENCH_DIV:
        case PGBENCH_MOD:
            {
                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;

                        default:
                            /* cannot get here */
                            Assert(0);
                    }
                }
                else            /* we have integer operands, or % */
                {
                    int64       li,
                                ri;

                    if (!coerceToInt(lval, &li) ||
                        !coerceToInt(rval, &ri))
                        return false;

                    switch (func)
                    {
                        case PGBENCH_ADD:
                            setIntValue(retval, li + ri);
                            return true;

                        case PGBENCH_SUB:
                            setIntValue(retval, li - ri);
                            return true;

                        case PGBENCH_MUL:
                            setIntValue(retval, li * ri);
                            return true;

                        case PGBENCH_DIV:
                        case PGBENCH_MOD:
                            if (ri == 0)
                            {
                                fprintf(stderr, "division by zero\n");
                                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)
                                    {
                                        fprintf(stderr, "bigint out of range\n");
                                        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);
                    }
                }
            }

            /* 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_INT)
                    fprintf(stderr, "int " INT64_FORMAT "\n", varg->u.ival);
                else
                {
                    Assert(varg->type == PGBT_DOUBLE);
                    fprintf(stderr, "double %.*g\n", DBL_DIG, varg->u.dval);
                }

                *retval = *varg;

                return true;
            }

            /* 1 double argument */
        case PGBENCH_DOUBLE:
        case PGBENCH_SQRT:
            {
                double      dval;

                Assert(nargs == 1);

                if (!coerceToDouble(&vargs[0], &dval))
                    return false;

                if (func == PGBENCH_SQRT)
                    dval = sqrt(dval);

                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:
            {
                int64       imin,
                            imax;

                Assert(nargs >= 2);

                if (!coerceToInt(&vargs[0], &imin) ||
                    !coerceToInt(&vargs[1], &imax))
                    return false;

                /* check random range */
                if (imin > imax)
                {
                    fprintf(stderr, "empty range given to random\n");
                    return false;
                }
                else if (imax - imin < 0 || (imax - imin) + 1 < 0)
                {
                    /* prevent int overflows in random functions */
                    fprintf(stderr, "random range is too large\n");
                    return false;
                }

                if (func == PGBENCH_RANDOM)
                {
                    Assert(nargs == 2);
                    setIntValue(retval, getrand(thread, 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)
                        {
                            fprintf(stderr,
                                    "gaussian parameter must be at least %f "
                                    "(not %f)\n", MIN_GAUSSIAN_PARAM, param);
                            return false;
                        }

                        setIntValue(retval,
                                    getGaussianRand(thread, imin, imax, param));
                    }
                    else        /* exponential */
                    {
                        if (param <= 0.0)
                        {
                            fprintf(stderr,
                                    "exponential parameter must be greater than zero"
                                    " (got %f)\n", param);
                            return false;
                        }

                        setIntValue(retval,
                                    getExponentialRand(thread, imin, imax, param));
                    }
                }

                return true;
            }

        default:
            /* cannot get here */
            Assert(0);
            /* dead code to avoid a compiler warning */
            return false;
    }
}

/*
 * 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(TState *thread, 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, expr->u.variable.varname)) == NULL)
                {
                    fprintf(stderr, "undefined variable \"%s\"\n",
                            expr->u.variable.varname);
                    return false;
                }

                if (!makeVariableNumeric(var))
                    return false;

                *retval = var->num_value;
                return true;
            }

        case ENODE_FUNCTION:
            return evalFunc(thread, st,
                            expr->u.function.function,
                            expr->u.function.args,
                            retval);

        default:
            /* internal error which should never occur */
            fprintf(stderr, "unexpected enode type in evaluation: %d\n",
                    expr->etype);
            exit(1);
    }
}

/*
 * 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(CState *st, 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(st, argv[i] + 1)) == NULL)
        {
            fprintf(stderr, "%s: undefined variable \"%s\"\n",
                    argv[0], argv[i]);
            return false;
        }

        arglen = strlen(arg);
        if (len + arglen + (i > 0 ? 1 : 0) >= SHELL_COMMAND_SIZE - 1)
        {
            fprintf(stderr, "%s: shell command is too long\n", argv[0]);
            return false;
        }

        if (i > 0)
            command[len++] = ' ';
        memcpy(command + len, arg, arglen);
        len += arglen;
    }

    command[len] = '\0';

    /* Fast path for non-assignment case */
    if (variable == NULL)
    {
        if (system(command))
        {
            if (!timer_exceeded)
                fprintf(stderr, "%s: could not launch shell command\n", argv[0]);
            return false;
        }
        return true;
    }

    /* Execute the command with pipe and read the standard output. */
    if ((fp = popen(command, "r")) == NULL)
    {
        fprintf(stderr, "%s: could not launch shell command\n", argv[0]);
        return false;
    }
    if (fgets(res, sizeof(res), fp) == NULL)
    {
        if (!timer_exceeded)
            fprintf(stderr, "%s: could not read result of shell command\n", argv[0]);
        (void) pclose(fp);
        return false;
    }
    if (pclose(fp) < 0)
    {
        fprintf(stderr, "%s: could not close shell command\n", 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')
    {
        fprintf(stderr, "%s: shell command must return an integer (not \"%s\")\n",
                argv[0], res);
        return false;
    }
    if (!putVariableInt(st, "setshell", variable, retval))
        return false;

#ifdef DEBUG
    printf("shell parameter name: \"%s\", value: \"%s\"\n", argv[1], res);
#endif
    return true;
}

#define MAX_PREPARE_NAME        32
static void
preparedStatementName(char *buffer, int file, int state)
{
    sprintf(buffer, "P%d_%d", file, state);
}

static void
commandFailed(CState *st, char *message)
{
    fprintf(stderr,
            "client %d aborted in command %d of script %d; %s\n",
            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, 0, total_weight - 1);
    do
    {
        w -= sql_script[i++].weight;
    } while (w >= 0);

    return i - 1;
}

/* 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, sql);

        if (debug)
            fprintf(stderr, "client %d sending %s\n", 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, command, params);

        if (debug)
            fprintf(stderr, "client %d sending %s\n", st->id, sql);
        r = PQsendQueryParams(st->con, sql, command->argc - 1,
                              NULL, params, NULL, NULL, 0);
    }
    else if (querymode == QUERY_PREPARED)
    {
        char        name[MAX_PREPARE_NAME];
        const char *params[MAX_ARGS];

        if (!st->prepared[st->use_file])
        {
            int         j;
            Command   **commands = sql_script[st->use_file].commands;

            for (j = 0; commands[j] != NULL; j++)
            {
                PGresult   *res;
                char        name[MAX_PREPARE_NAME];

                if (commands[j]->type != SQL_COMMAND)
                    continue;
                preparedStatementName(name, st->use_file, j);
                res = PQprepare(st->con, name,
                                commands[j]->argv[0], commands[j]->argc - 1, NULL);
                if (PQresultStatus(res) != PGRES_COMMAND_OK)
                    fprintf(stderr, "%s", PQerrorMessage(st->con));
                PQclear(res);
            }
            st->prepared[st->use_file] = true;
        }

        getQueryParams(st, command, params);
        preparedStatementName(name, st->use_file, st->command);

        if (debug)
            fprintf(stderr, "client %d sending %s\n", st->id, name);
        r = PQsendQueryPrepared(st->con, name, command->argc - 1,
                                params, NULL, NULL, 0);
    }
    else                        /* unknown sql mode */
        r = 0;

    if (r == 0)
    {
        if (debug)
            fprintf(stderr, "client %d could not send %s\n",
                    st->id, command->argv[0]);
        st->ecnt++;
        return false;
    }
    else
        return true;
}

/*
 * 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(CState *st, int argc, char **argv, int *usecs)
{
    char       *var;
    int         usec;

    if (*argv[1] == ':')
    {
        if ((var = getVariable(st, argv[1] + 1)) == NULL)
        {
            fprintf(stderr, "%s: undefined variable \"%s\"\n",
                    argv[0], argv[1]);
            return false;
        }
        usec = atoi(var);
    }
    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;
}

/*
 * Advance the state machine of a connection, if possible.
 */
static void
doCustom(TState *thread, CState *st, StatsData *agg)
{
    PGresult   *res;
    Command    *command;
    instr_time  now;
    bool        end_tx_processed = false;
    int64       wait;

    /*
     * 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.
     */
    INSTR_TIME_SET_ZERO(now);

    /*
     * Loop in the state machine, until we have to wait for a result from the
     * server (or have to sleep, for throttling or for \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.
     */
    for (;;)
    {
        switch (st->state)
        {
                /*
                 * Select transaction to run.
                 */
            case CSTATE_CHOOSE_SCRIPT:

                st->use_file = chooseScript(thread);

                if (debug)
                    fprintf(stderr, "client %d executing script \"%s\"\n", st->id,
                            sql_script[st->use_file].desc);

                if (throttle_delay > 0)
                    st->state = CSTATE_START_THROTTLE;
                else
                    st->state = CSTATE_START_TX;
                break;

                /*
                 * Handle throttling once per transaction by sleeping.
                 */
            case CSTATE_START_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);
                wait = getPoissonRand(thread, throttle_delay);

                thread->throttle_trigger += wait;
                st->txn_scheduled = thread->throttle_trigger;

                /*
                 * stop client if next transaction is beyond pgbench end of
                 * execution
                 */
                if (duration > 0 && st->txn_scheduled > end_time)
                {
                    st->state = CSTATE_FINISHED;
                    break;
                }

                /*
                 * 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, we skip this time slot and
                 * iterate till the next slot that isn't late yet.  But don't
                 * iterate beyond the -t limit, if one is given.
                 */
                if (latency_limit)
                {
                    int64       now_us;

                    if (INSTR_TIME_IS_ZERO(now))
                        INSTR_TIME_SET_CURRENT(now);
                    now_us = INSTR_TIME_GET_MICROSEC(now);
                    while (thread->throttle_trigger < now_us - latency_limit &&
                           (nxacts <= 0 || st->cnt < nxacts))
                    {
                        processXactStats(thread, st, &now, true, agg);
                        /* next rendez-vous */
                        wait = getPoissonRand(thread, throttle_delay);
                        thread->throttle_trigger += wait;
                        st->txn_scheduled = thread->throttle_trigger;
                    }
                    /* stop client if -t exceeded */
                    if (nxacts > 0 && st->cnt >= nxacts)
                    {
                        st->state = CSTATE_FINISHED;
                        break;
                    }
                }

                st->state = CSTATE_THROTTLE;
                if (debug)
                    fprintf(stderr, "client %d throttling " INT64_FORMAT " us\n",
                            st->id, wait);
                break;

                /*
                 * Wait until it's time to start next transaction.
                 */
            case CSTATE_THROTTLE:
                if (INSTR_TIME_IS_ZERO(now))
                    INSTR_TIME_SET_CURRENT(now);
                if (INSTR_TIME_GET_MICROSEC(now) < st->txn_scheduled)
                    return;     /* Still sleeping, nothing to do here */

                /* Else done sleeping, start the transaction */
                st->state = CSTATE_START_TX;
                break;

                /* Start new transaction */
            case CSTATE_START_TX:

                /*
                 * Establish connection on first call, or if is_connect is
                 * true.
                 */
                if (st->con == NULL)
                {
                    instr_time  start;

                    if (INSTR_TIME_IS_ZERO(now))
                        INSTR_TIME_SET_CURRENT(now);
                    start = now;
                    if ((st->con = doConnect()) == NULL)
                    {
                        fprintf(stderr, "client %d aborted while establishing connection\n",
                                st->id);
                        st->state = CSTATE_ABORTED;
                        break;
                    }
                    INSTR_TIME_SET_CURRENT(now);
                    INSTR_TIME_ACCUM_DIFF(thread->conn_time, now, start);

                    /* Reset session-local state */
                    memset(st->prepared, 0, sizeof(st->prepared));
                }

                /*
                 * Record transaction start time under logging, progress or
                 * throttling.
                 */
                if (use_log || progress || throttle_delay || latency_limit ||
                    per_script_stats)
                {
                    if (INSTR_TIME_IS_ZERO(now))
                        INSTR_TIME_SET_CURRENT(now);
                    st->txn_begin = now;

                    /*
                     * When not throttling, this is also the transaction's
                     * scheduled start time.
                     */
                    if (!throttle_delay)
                        st->txn_scheduled = INSTR_TIME_GET_MICROSEC(now);
                }

                /* Begin with the first command */
                st->command = 0;
                st->state = CSTATE_START_COMMAND;
                break;

                /*
                 * Send a command to server (or execute a meta-command)
                 */
            case CSTATE_START_COMMAND:
                command = sql_script[st->use_file].commands[st->command];

                /*
                 * If we reached the end of the script, move to end-of-xact
                 * processing.
                 */
                if (command == NULL)
                {
                    st->state = CSTATE_END_TX;
                    break;
                }

                /*
                 * Record statement start time if per-command latencies are
                 * requested
                 */
                if (is_latencies)
                {
                    if (INSTR_TIME_IS_ZERO(now))
                        INSTR_TIME_SET_CURRENT(now);
                    st->stmt_begin = now;
                }

                if (command->type == SQL_COMMAND)
                {
                    if (!sendCommand(st, command))
                    {
                        commandFailed(st, "SQL command send failed");
                        st->state = CSTATE_ABORTED;
                    }
                    else
                        st->state = CSTATE_WAIT_RESULT;
                }
                else if (command->type == META_COMMAND)
                {
                    int         argc = command->argc,
                                i;
                    char      **argv = command->argv;

                    if (debug)
                    {
                        fprintf(stderr, "client %d executing \\%s", st->id, argv[0]);
                        for (i = 1; i < argc; i++)
                            fprintf(stderr, " %s", argv[i]);
                        fprintf(stderr, "\n");
                    }

                    if (pg_strcasecmp(argv[0], "sleep") == 0)
                    {
                        /*
                         * 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.)
                         */
                        int         usec;

                        if (!evaluateSleep(st, argc, argv, &usec))
                        {
                            commandFailed(st, "execution of meta-command 'sleep' failed");
                            st->state = CSTATE_ABORTED;
                            break;
                        }

                        if (INSTR_TIME_IS_ZERO(now))
                            INSTR_TIME_SET_CURRENT(now);
                        st->sleep_until = INSTR_TIME_GET_MICROSEC(now) + usec;
                        st->state = CSTATE_SLEEP;
                        break;
                    }
                    else
                    {
                        if (pg_strcasecmp(argv[0], "set") == 0)
                        {
                            PgBenchExpr *expr = command->expr;
                            PgBenchValue result;

                            if (!evaluateExpr(thread, st, expr, &result))
                            {
                                commandFailed(st, "evaluation of meta-command 'set' failed");
                                st->state = CSTATE_ABORTED;
                                break;
                            }

                            if (!putVariableNumber(st, argv[0], argv[1], &result))
                            {
                                commandFailed(st, "assignment of meta-command 'set' failed");
                                st->state = CSTATE_ABORTED;
                                break;
                            }
                        }
                        else if (pg_strcasecmp(argv[0], "setshell") == 0)
                        {
                            bool        ret = runShellCommand(st, argv[1], argv + 2, argc - 2);

                            if (timer_exceeded) /* timeout */
                            {
                                st->state = CSTATE_FINISHED;
                                break;
                            }
                            else if (!ret)  /* on error */
                            {
                                commandFailed(st, "execution of meta-command 'setshell' failed");
                                st->state = CSTATE_ABORTED;
                                break;
                            }
                            else
                            {
                                /* succeeded */
                            }
                        }
                        else if (pg_strcasecmp(argv[0], "shell") == 0)
                        {
                            bool        ret = runShellCommand(st, NULL, argv + 1, argc - 1);

                            if (timer_exceeded) /* timeout */
                            {
                                st->state = CSTATE_FINISHED;
                                break;
                            }
                            else if (!ret)  /* on error */
                            {
                                commandFailed(st, "execution of meta-command 'shell' failed");
                                st->state = CSTATE_ABORTED;
                                break;
                            }
                            else
                            {
                                /* succeeded */
                            }
                        }

                        /*
                         * executing the expression or shell command might
                         * take a non-negligible amount of time, so reset
                         * 'now'
                         */
                        INSTR_TIME_SET_ZERO(now);

                        st->state = CSTATE_END_COMMAND;
                    }
                }
                break;

                /*
                 * Wait for the current SQL command to complete
                 */
            case CSTATE_WAIT_RESULT:
                command = sql_script[st->use_file].commands[st->command];
                if (debug)
                    fprintf(stderr, "client %d receiving\n", st->id);
                if (!PQconsumeInput(st->con))
                {               /* there's something wrong */
                    commandFailed(st, "perhaps the backend died while processing");
                    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:
                    case PGRES_TUPLES_OK:
                    case PGRES_EMPTY_QUERY:
                        /* OK */
                        PQclear(res);
                        discard_response(st);
                        st->state = CSTATE_END_COMMAND;
                        break;
                    default:
                        commandFailed(st, PQerrorMessage(st->con));
                        PQclear(res);
                        st->state = CSTATE_ABORTED;
                        break;
                }
                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:
                if (INSTR_TIME_IS_ZERO(now))
                    INSTR_TIME_SET_CURRENT(now);
                if (INSTR_TIME_GET_MICROSEC(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 (is_latencies)
                {
                    if (INSTR_TIME_IS_ZERO(now))
                        INSTR_TIME_SET_CURRENT(now);

                    /* XXX could use a mutex here, but we choose not to */
                    command = sql_script[st->use_file].commands[st->command];
                    addToSimpleStats(&command->stats,
                                     INSTR_TIME_GET_DOUBLE(now) -
                                     INSTR_TIME_GET_DOUBLE(st->stmt_begin));
                }

                /* Go ahead with next command */
                st->command++;
                st->state = CSTATE_START_COMMAND;
                break;

                /*
                 * End of transaction.
                 */
            case CSTATE_END_TX:

                /* transaction finished: calculate latency and do log */
                processXactStats(thread, st, &now, false, agg);

                if (is_connect)
                {
                    PQfinish(st->con);
                    st->con = NULL;
                    INSTR_TIME_SET_ZERO(now);
                }

                if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
                {
                    /* exit success */
                    st->state = CSTATE_FINISHED;
                    break;
                }

                /*
                 * No transaction is underway anymore.
                 */
                st->state = CSTATE_CHOOSE_SCRIPT;

                /*
                 * If we paced through all commands in the script in this
                 * loop, without returning to the caller even once, do it now.
                 * This gives the thread a chance to process other
                 * connections, and to do progress reporting.  This can
                 * currently only happen if the script consists entirely of
                 * meta-commands.
                 */
                if (end_tx_processed)
                    return;
                else
                {
                    end_tx_processed = true;
                    break;
                }

                /*
                 * Final states.  Close the connection if it's still open.
                 */
            case CSTATE_ABORTED:
            case CSTATE_FINISHED:
                if (st->con != NULL)
                {
                    PQfinish(st->con);
                    st->con = NULL;
                }
                return;
        }
    }
}

/*
 * Print log entry after completing one transaction.
 *
 * We print Unix-epoch timestamps in the log, so that entries can be
 * correlated against other logs.  On some platforms this could be obtained
 * from the instr_time reading the caller has, but rather than get entangled
 * with that, we just eat the cost of an extra syscall in all cases.
 */
static void
doLog(TState *thread, CState *st,
      StatsData *agg, bool skipped, double latency, double lag)
{
    FILE       *logfile = thread->logfile;

    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_erand48(thread->random_state) > sample_rate)
        return;

    /* should we aggregate the results or not? */
    if (agg_interval > 0)
    {
        /*
         * 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).
         */
        time_t      now = time(NULL);

        while (agg->start_time + agg_interval <= now)
        {
            /* print aggregated report to logfile */
            fprintf(logfile, "%ld " INT64_FORMAT " %.0f %.0f %.0f %.0f",
                    (long) agg->start_time,
                    agg->cnt,
                    agg->latency.sum,
                    agg->latency.sum2,
                    agg->latency.min,
                    agg->latency.max);
            if (throttle_delay)
            {
                fprintf(logfile, " %.0f %.0f %.0f %.0f",
                        agg->lag.sum,
                        agg->lag.sum2,
                        agg->lag.min,
                        agg->lag.max);
                if (latency_limit)
                    fprintf(logfile, " " INT64_FORMAT, agg->skipped);
            }
            fputc('\n', logfile);

            /* reset data and move to next interval */
            initStats(agg, agg->start_time + agg_interval);
        }

        /* accumulate the current transaction */
        accumStats(agg, skipped, latency, lag);
    }
    else
    {
        /* no, print raw transactions */
        struct timeval tv;

        gettimeofday(&tv, NULL);
        if (skipped)
            fprintf(logfile, "%d " INT64_FORMAT " skipped %d %ld %ld",
                    st->id, st->cnt, st->use_file,
                    (long) tv.tv_sec, (long) tv.tv_usec);
        else
            fprintf(logfile, "%d " INT64_FORMAT " %.0f %d %ld %ld",
                    st->id, st->cnt, latency, st->use_file,
                    (long) tv.tv_sec, (long) tv.tv_usec);
        if (throttle_delay)
            fprintf(logfile, " %.0f", lag);
        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 transactions are counted in the "cnt" fields.)
 */
static void
processXactStats(TState *thread, CState *st, instr_time *now,
                 bool skipped, StatsData *agg)
{
    double      latency = 0.0,
                lag = 0.0;
    bool        thread_details = progress || throttle_delay || latency_limit,
                detailed = thread_details || use_log || per_script_stats;

    if (detailed && !skipped)
    {
        if (INSTR_TIME_IS_ZERO(*now))
            INSTR_TIME_SET_CURRENT(*now);

        /* compute latency & lag */
        latency = INSTR_TIME_GET_MICROSEC(*now) - st->txn_scheduled;
        lag = INSTR_TIME_GET_MICROSEC(st->txn_begin) - st->txn_scheduled;
    }

    if (thread_details)
    {
        /* keep detailed thread stats */
        accumStats(&thread->stats, skipped, latency, lag);

        /* count transactions over the latency limit, if needed */
        if (latency_limit && latency > latency_limit)
            thread->latency_late++;
    }
    else
    {
        /* no detailed stats, just count */
        thread->stats.cnt++;
    }

    /* 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);
}


/* discard connections */
static void
disconnect_all(CState *state, int length)
{
    int         i;

    for (i = 0; i < length; i++)
    {
        if (state[i].con)
        {
            PQfinish(state[i].con);
            state[i].con = NULL;
        }
    }
}

/* create tables and setup data */
static void
init(bool is_no_vacuum)
{
/*
 * The scale factor at/beyond which 32-bit integers are insufficient for
 * storing TPC-B account IDs.
 *
 * 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

    /*
     * 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
        }
    };
    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)"
    };
    static const char *const DDLKEYs[] = {
        "alter table pgbench_tellers add foreign key (bid) references pgbench_branches",
        "alter table pgbench_accounts add foreign key (bid) references pgbench_branches",
        "alter table pgbench_history add foreign key (bid) references pgbench_branches",
        "alter table pgbench_history add foreign key (tid) references pgbench_tellers",
        "alter table pgbench_history add foreign key (aid) references pgbench_accounts"
    };

    PGconn     *con;
    PGresult   *res;
    char        sql[256];
    int         i;
    int64       k;

    /* used to track elapsed time and estimate of the remaining time */
    instr_time  start,
                diff;
    double      elapsed_sec,
                remaining_sec;
    int         log_interval = 1;

    if ((con = doConnect()) == NULL)
        exit(1);

    for (i = 0; i < lengthof(DDLs); i++)
    {
        char        opts[256];
        char        buffer[256];
        const struct ddlinfo *ddl = &DDLs[i];
        const char *cols;

        /* Remove old table, if it exists. */
        snprintf(buffer, sizeof(buffer), "drop table if exists %s", ddl->table);
        executeStatement(con, buffer);

        /* Construct new create table statement. */
        opts[0] = '\0';
        if (ddl->declare_fillfactor)
            snprintf(opts + strlen(opts), sizeof(opts) - strlen(opts),
                     " with (fillfactor=%d)", fillfactor);
        if (tablespace != NULL)
        {
            char       *escape_tablespace;

            escape_tablespace = PQescapeIdentifier(con, tablespace,
                                                   strlen(tablespace));
            snprintf(opts + strlen(opts), sizeof(opts) - strlen(opts),
                     " tablespace %s", escape_tablespace);
            PQfreemem(escape_tablespace);
        }

        cols = (scale >= SCALE_32BIT_THRESHOLD) ? ddl->bigcols : ddl->smcols;

        snprintf(buffer, sizeof(buffer), "create%s table %s(%s)%s",
                 unlogged_tables ? " unlogged" : "",
                 ddl->table, cols, opts);

        executeStatement(con, buffer);
    }

    executeStatement(con, "begin");

    for (i = 0; i < nbranches * scale; i++)
    {
        /* "filler" column defaults to NULL */
        snprintf(sql, sizeof(sql),
                 "insert into pgbench_branches(bid,bbalance) values(%d,0)",
                 i + 1);
        executeStatement(con, sql);
    }

    for (i = 0; i < ntellers * scale; i++)
    {
        /* "filler" column defaults to NULL */
        snprintf(sql, sizeof(sql),
                 "insert into pgbench_tellers(tid,bid,tbalance) values (%d,%d,0)",
                 i + 1, i / ntellers + 1);
        executeStatement(con, sql);
    }

    executeStatement(con, "commit");

    /*
     * fill the pgbench_accounts table with some data
     */
    fprintf(stderr, "creating tables...\n");

    executeStatement(con, "begin");
    executeStatement(con, "truncate pgbench_accounts");

    res = PQexec(con, "copy pgbench_accounts from stdin");
    if (PQresultStatus(res) != PGRES_COPY_IN)
    {
        fprintf(stderr, "%s", PQerrorMessage(con));
        exit(1);
    }
    PQclear(res);

    INSTR_TIME_SET_CURRENT(start);

    for (k = 0; k < (int64) naccounts * scale; k++)
    {
        int64       j = k + 1;

        /* "filler" column defaults to blank padded empty string */
        snprintf(sql, sizeof(sql),
                 INT64_FORMAT "\t" INT64_FORMAT "\t%d\t\n",
                 j, k / naccounts + 1, 0);
        if (PQputline(con, sql))
        {
            fprintf(stderr, "PQputline failed\n");
            exit(1);
        }

        /*
         * If we want to stick with the original logging, print a message each
         * 100k inserted rows.
         */
        if ((!use_quiet) && (j % 100000 == 0))
        {
            INSTR_TIME_SET_CURRENT(diff);
            INSTR_TIME_SUBTRACT(diff, start);

            elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
            remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;

            fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)\n",
                    j, (int64) naccounts * scale,
                    (int) (((int64) j * 100) / (naccounts * (int64) scale)),
                    elapsed_sec, remaining_sec);
        }
        /* let's not call the timing for each row, but only each 100 rows */
        else if (use_quiet && (j % 100 == 0))
        {
            INSTR_TIME_SET_CURRENT(diff);
            INSTR_TIME_SUBTRACT(diff, start);

            elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
            remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;

            /* have we reached the next interval (or end)? */
            if ((j == scale * naccounts) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
            {
                fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)\n",
                        j, (int64) naccounts * scale,
                        (int) (((int64) j * 100) / (naccounts * (int64) scale)), elapsed_sec, remaining_sec);

                /* skip to the next interval */
                log_interval = (int) ceil(elapsed_sec / LOG_STEP_SECONDS);
            }
        }

    }
    if (PQputline(con, "\\.\n"))
    {
        fprintf(stderr, "very last PQputline failed\n");
        exit(1);
    }
    if (PQendcopy(con))
    {
        fprintf(stderr, "PQendcopy failed\n");
        exit(1);
    }
    executeStatement(con, "commit");

    /* vacuum */
    if (!is_no_vacuum)
    {
        fprintf(stderr, "vacuum...\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 indexes
     */
    fprintf(stderr, "set primary keys...\n");
    for (i = 0; i < lengthof(DDLINDEXes); i++)
    {
        char        buffer[256];

        strlcpy(buffer, DDLINDEXes[i], sizeof(buffer));

        if (index_tablespace != NULL)
        {
            char       *escape_tablespace;

            escape_tablespace = PQescapeIdentifier(con, index_tablespace,
                                                   strlen(index_tablespace));
            snprintf(buffer + strlen(buffer), sizeof(buffer) - strlen(buffer),
                     " using index tablespace %s", escape_tablespace);
            PQfreemem(escape_tablespace);
        }

        executeStatement(con, buffer);
    }

    /*
     * create foreign keys
     */
    if (foreign_keys)
    {
        fprintf(stderr, "set foreign keys...\n");
        for (i = 0; i < lengthof(DDLKEYs); i++)
        {
            executeStatement(con, DDLKEYs[i]);
        }
    }

    fprintf(stderr, "done.\n");
    PQfinish(con);
}

/*
 * Replace :param with $n throughout the command's SQL text, which
 * is a modifiable string in cmd->argv[0].
 */
static bool
parseQuery(Command *cmd)
{
    char       *sql,
               *p;

    /* We don't want to scribble on cmd->argv[0] until done */
    sql = pg_strdup(cmd->argv[0]);

    cmd->argc = 1;

    p = sql;
    while ((p = strchr(p, ':')) != NULL)
    {
        char        var[12];
        char       *name;
        int         eaten;

        name = parseVariable(p, &eaten);
        if (name == NULL)
        {
            while (*p == ':')
            {
                p++;
            }
            continue;
        }

        if (cmd->argc >= MAX_ARGS)
        {
            fprintf(stderr, "statement has too many arguments (maximum is %d): %s\n",
                    MAX_ARGS - 1, cmd->argv[0]);
            pg_free(name);
            return false;
        }

        sprintf(var, "$%d", cmd->argc);
        p = replaceVariable(&sql, p, eaten, var);

        cmd->argv[cmd->argc] = name;
        cmd->argc++;
    }

    pg_free(cmd->argv[0]);
    cmd->argv[0] = sql;
    return true;
}

/*
 * Simple error-printing function, might be needed by lexer
 */
static void
pgbench_error(const char *fmt,...)
{
    va_list     ap;

    fflush(stdout);
    va_start(ap, fmt);
    vfprintf(stderr, _(fmt), ap);
    va_end(ap);
}

/*
 * 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)
{
    fprintf(stderr, "%s:%d: %s", source, lineno, msg);
    if (more != NULL)
        fprintf(stderr, " (%s)", more);
    if (column >= 0 && line == NULL)
        fprintf(stderr, " at column %d", column + 1);
    if (command != NULL)
        fprintf(stderr, " in command \"%s\"", command);
    fprintf(stderr, "\n");
    if (line != NULL)
    {
        fprintf(stderr, "%s\n", line);
        if (column >= 0)
        {
            int         i;

            for (i = 0; i < column; i++)
                fprintf(stderr, " ");
            fprintf(stderr, "^ error found here\n");
        }
    }
    exit(1);
}

/*
 * Parse a SQL command; return a Command struct, or NULL if it's a comment
 *
 * On entry, psqlscan.l has collected the command into "buf", so we don't
 * really need to do much here except check for comment and set up a
 * Command struct.
 */
static Command *
process_sql_command(PQExpBuffer buf, const char *source)
{
    Command    *my_command;
    char       *p;
    char       *nlpos;

    /* Skip any leading whitespace, as well as "--" style comments */
    p = buf->data;
    for (;;)
    {
        if (isspace((unsigned char) *p))
            p++;
        else if (strncmp(p, "--", 2) == 0)
        {
            p = strchr(p, '\n');
            if (p == NULL)
                return NULL;
            p++;
        }
        else
            break;
    }

    /* If there's nothing but whitespace and comments, we're done */
    if (*p == '\0')
        return NULL;

    /* Allocate and initialize Command structure */
    my_command = (Command *) pg_malloc0(sizeof(Command));
    my_command->command_num = num_commands++;
    my_command->type = SQL_COMMAND;
    initSimpleStats(&my_command->stats);

    /*
     * Install query text as the sole argv string.  If we are using a
     * non-simple query mode, we'll extract parameters from it later.
     */
    my_command->argv[0] = pg_strdup(p);
    my_command->argc = 1;

    /*
     * If SQL command is multi-line, we only want to save the first line as
     * the "line" label.
     */
    nlpos = strchr(p, '\n');
    if (nlpos)
    {
        my_command->line = pg_malloc(nlpos - p + 1);
        memcpy(my_command->line, p, nlpos - p);
        my_command->line[nlpos - p] = '\0';
    }
    else
        my_command->line = pg_strdup(p);

    return my_command;
}

/*
 * Parse a backslash command; return a Command struct, or NULL if comment
 *
 * At call, we have scanned only the initial backslash.
 */
static Command *
process_backslash_command(PsqlScanState sstate, const char *source)
{
    Command    *my_command;
    PQExpBufferData word_buf;
    int         word_offset;
    int         offsets[MAX_ARGS];  /* offsets of argument words */
    int         start_offset;
    int         lineno;
    int         j;

    initPQExpBuffer(&word_buf);

    /* Remember location of the backslash */
    start_offset = expr_scanner_offset(sstate) - 1;
    lineno = expr_scanner_get_lineno(sstate, start_offset);

    /* Collect first word of command */
    if (!expr_lex_one_word(sstate, &word_buf, &word_offset))
    {
        termPQExpBuffer(&word_buf);
        return NULL;
    }

    /* Allocate and initialize Command structure */
    my_command = (Command *) pg_malloc0(sizeof(Command));
    my_command->command_num = num_commands++;
    my_command->type = META_COMMAND;
    my_command->argc = 0;
    initSimpleStats(&my_command->stats);

    /* Save first word (command name) */
    j = 0;
    offsets[j] = word_offset;
    my_command->argv[j++] = pg_strdup(word_buf.data);
    my_command->argc++;

    if (pg_strcasecmp(my_command->argv[0], "set") == 0)
    {
        /* For \set, collect var name, then lex the expression. */
        yyscan_t    yyscanner;

        if (!expr_lex_one_word(sstate, &word_buf, &word_offset))
            syntax_error(source, lineno, my_command->line, my_command->argv[0],
                         "missing argument", NULL, -1);

        offsets[j] = word_offset;
        my_command->argv[j++] = pg_strdup(word_buf.data);
        my_command->argc++;

        yyscanner = expr_scanner_init(sstate, source, lineno, start_offset,
                                      my_command->argv[0]);

        if (expr_yyparse(yyscanner) != 0)
        {
            /* dead code: exit done from syntax_error called by yyerror */
            exit(1);
        }

        my_command->expr = expr_parse_result;

        /* Save line, trimming any trailing newline */
        my_command->line = expr_scanner_get_substring(sstate,
                                                      start_offset,
                                                      expr_scanner_offset(sstate),
                                                      true);

        expr_scanner_finish(yyscanner);

        termPQExpBuffer(&word_buf);

        return my_command;
    }

    /* For all other commands, collect remaining words. */
    while (expr_lex_one_word(sstate, &word_buf, &word_offset))
    {
        if (j >= MAX_ARGS)
            syntax_error(source, lineno, my_command->line, my_command->argv[0],
                         "too many arguments", NULL, -1);

        offsets[j] = word_offset;
        my_command->argv[j++] = pg_strdup(word_buf.data);
        my_command->argc++;
    }

    /* Save line, trimming any trailing newline */
    my_command->line = expr_scanner_get_substring(sstate,
                                                  start_offset,
                                                  expr_scanner_offset(sstate),
                                                  true);

    if (pg_strcasecmp(my_command->argv[0], "sleep") == 0)
    {
        if (my_command->argc < 2)
            syntax_error(source, lineno, my_command->line, my_command->argv[0],
                         "missing argument", NULL, -1);

        if (my_command->argc > 3)
            syntax_error(source, lineno, my_command->line, my_command->argv[0],
                         "too many arguments", NULL,
                         offsets[3] - start_offset);

        /*
         * Split argument into number and unit to allow "sleep 1ms" etc. We
         * don't have to terminate the number argument with null because it
         * will be parsed with atoi, which ignores trailing non-digit
         * characters.
         */
        if (my_command->argc == 2 && my_command->argv[1][0] != ':')
        {
            char       *c = my_command->argv[1];

            while (isdigit((unsigned char) *c))
                c++;
            if (*c)
            {
                my_command->argv[2] = c;
                offsets[2] = offsets[1] + (c - my_command->argv[1]);
                my_command->argc = 3;
            }
        }

        if (my_command->argc == 3)
        {
            if (pg_strcasecmp(my_command->argv[2], "us") != 0 &&
                pg_strcasecmp(my_command->argv[2], "ms") != 0 &&
                pg_strcasecmp(my_command->argv[2], "s") != 0)
                syntax_error(source, lineno, my_command->line, my_command->argv[0],
                             "unrecognized time unit, must be us, ms or s",
                             my_command->argv[2], offsets[2] - start_offset);
        }
    }
    else if (pg_strcasecmp(my_command->argv[0], "setshell") == 0)
    {
        if (my_command->argc < 3)
            syntax_error(source, lineno, my_command->line, my_command->argv[0],
                         "missing argument", NULL, -1);
    }
    else if (pg_strcasecmp(my_command->argv[0], "shell") == 0)
    {
        if (my_command->argc < 2)
            syntax_error(source, lineno, my_command->line, my_command->argv[0],
                         "missing command", NULL, -1);
    }
    else
    {
        syntax_error(source, lineno, my_command->line, my_command->argv[0],
                     "invalid command", NULL, -1);
    }

    termPQExpBuffer(&word_buf);

    return my_command;
}

/*
 * Parse a script (either the contents of a file, or a built-in script)
 * and add it to the list of scripts.
 */
static void
ParseScript(const char *script, const char *desc, int weight)
{
    ParsedScript ps;
    PsqlScanState sstate;
    PQExpBufferData line_buf;
    int         alloc_num;
    int         index;

#define COMMANDS_ALLOC_NUM 128
    alloc_num = COMMANDS_ALLOC_NUM;

    /* Initialize all fields of ps */
    ps.desc = desc;
    ps.weight = weight;
    ps.commands = (Command **) pg_malloc(sizeof(Command *) * alloc_num);
    initStats(&ps.stats, 0);

    /* Prepare to parse script */
    sstate = psql_scan_create(&pgbench_callbacks);

    /*
     * Ideally, we'd scan scripts using the encoding and stdstrings settings
     * we get from a DB connection.  However, without major rearrangement of
     * pgbench's argument parsing, we can't have a DB connection at the time
     * we parse scripts.  Using SQL_ASCII (encoding 0) should work well enough
     * with any backend-safe encoding, though conceivably we could be fooled
     * if a script file uses a client-only encoding.  We also assume that
     * stdstrings should be true, which is a bit riskier.
     */
    psql_scan_setup(sstate, script, strlen(script), 0, true);

    initPQExpBuffer(&line_buf);

    index = 0;

    for (;;)
    {
        PsqlScanResult sr;
        promptStatus_t prompt;
        Command    *command;

        resetPQExpBuffer(&line_buf);

        sr = psql_scan(sstate, &line_buf, &prompt);

        /* If we collected a SQL command, process that */
        command = process_sql_command(&line_buf, desc);
        if (command)
        {
            ps.commands[index] = command;
            index++;

            if (index >= alloc_num)
            {
                alloc_num += COMMANDS_ALLOC_NUM;
                ps.commands = (Command **)
                    pg_realloc(ps.commands, sizeof(Command *) * alloc_num);
            }
        }

        /* If we reached a backslash, process that */
        if (sr == PSCAN_BACKSLASH)
        {
            command = process_backslash_command(sstate, desc);
            if (command)
            {
                ps.commands[index] = command;
                index++;

                if (index >= alloc_num)
                {
                    alloc_num += COMMANDS_ALLOC_NUM;
                    ps.commands = (Command **)
                        pg_realloc(ps.commands, sizeof(Command *) * alloc_num);
                }
            }
        }

        /* Done if we reached EOF */
        if (sr == PSCAN_INCOMPLETE || sr == PSCAN_EOL)
            break;
    }

    ps.commands[index] = NULL;

    addScript(ps);

    termPQExpBuffer(&line_buf);
    psql_scan_finish(sstate);
    psql_scan_destroy(sstate);
}

/*
 * Read the entire contents of file fd, and return it in a malloc'd buffer.
 *
 * The buffer will typically be larger than necessary, but we don't care
 * in this program, because we'll free it as soon as we've parsed the script.
 */
static char *
read_file_contents(FILE *fd)
{
    char       *buf;
    size_t      buflen = BUFSIZ;
    size_t      used = 0;

    buf = (char *) pg_malloc(buflen);

    for (;;)
    {
        size_t      nread;

        nread = fread(buf + used, 1, BUFSIZ, fd);
        used += nread;
        /* If fread() read less than requested, must be EOF or error */
        if (nread < BUFSIZ)
            break;
        /* Enlarge buf so we can read some more */
        buflen += BUFSIZ;
        buf = (char *) pg_realloc(buf, buflen);
    }
    /* There is surely room for a terminator */
    buf[used] = '\0';

    return buf;
}

/*
 * Given a file name, read it and add its script to the list.
 * "-" means to read stdin.
 * NB: filename must be storage that won't disappear.
 */
static void
process_file(const char *filename, int weight)
{
    FILE       *fd;
    char       *buf;

    /* Slurp the file contents into "buf" */
    if (strcmp(filename, "-") == 0)
        fd = stdin;
    else if ((fd = fopen(filename, "r")) == NULL)
    {
        fprintf(stderr, "could not open file \"%s\": %s\n",
                filename, strerror(errno));
        exit(1);
    }

    buf = read_file_contents(fd);

    if (ferror(fd))
    {
        fprintf(stderr, "could not read file \"%s\": %s\n",
                filename, strerror(errno));
        exit(1);
    }

    if (fd != stdin)
        fclose(fd);

    ParseScript(buf, filename, weight);

    free(buf);
}

/* Parse the given builtin script and add it to the list. */
static void
process_builtin(const BuiltinScript *bi, int weight)
{
    ParseScript(bi->script, bi->desc, weight);
}

/* show available builtin scripts */
static void
listAvailableScripts(void)
{
    int         i;

    fprintf(stderr, "Available builtin scripts:\n");
    for (i = 0; i < lengthof(builtin_script); i++)
        fprintf(stderr, "\t%s\n", builtin_script[i].name);
    fprintf(stderr, "\n");
}

/* return builtin script "name" if unambiguous, fails if not found */
static const BuiltinScript *
findBuiltin(const char *name)
{
    int         i,
                found = 0,
                len = strlen(name);
    const BuiltinScript *result = NULL;

    for (i = 0; i < lengthof(builtin_script); i++)
    {
        if (strncmp(builtin_script[i].name, name, len) == 0)
        {
            result = &builtin_script[i];
            found++;
        }
    }

    /* ok, unambiguous result */
    if (found == 1)
        return result;

    /* error cases */
    if (found == 0)
        fprintf(stderr, "no builtin script found for name \"%s\"\n", name);
    else                        /* found > 1 */
        fprintf(stderr,
                "ambiguous builtin name: %d builtin scripts found for prefix \"%s\"\n", found, name);

    listAvailableScripts();
    exit(1);
}

/*
 * Determine the weight specification from a script option (-b, -f), if any,
 * and return it as an integer (1 is returned if there's no weight).  The
 * script name is returned in *script as a malloc'd string.
 */
static int
parseScriptWeight(const char *option, char **script)
{
    char       *sep;
    int         weight;

    if ((sep = strrchr(option, WSEP)))
    {
        int         namelen = sep - option;
        long        wtmp;
        char       *badp;

        /* generate the script name */
        *script = pg_malloc(namelen + 1);
        strncpy(*script, option, namelen);
        (*script)[namelen] = '\0';

        /* process digits of the weight spec */
        errno = 0;
        wtmp = strtol(sep + 1, &badp, 10);
        if (errno != 0 || badp == sep + 1 || *badp != '\0')
        {
            fprintf(stderr, "invalid weight specification: %s\n", sep);
            exit(1);
        }
        if (wtmp > INT_MAX || wtmp < 0)
        {
            fprintf(stderr,
                    "weight specification out of range (0 .. %u): " INT64_FORMAT "\n",
                    INT_MAX, (int64) wtmp);
            exit(1);
        }
        weight = wtmp;
    }
    else
    {
        *script = pg_strdup(option);
        weight = 1;
    }

    return weight;
}

/* append a script to the list of scripts to process */
static void
addScript(ParsedScript script)
{
    if (script.commands == NULL || script.commands[0] == NULL)
    {
        fprintf(stderr, "empty command list for script \"%s\"\n", script.desc);
        exit(1);
    }

    if (num_scripts >= MAX_SCRIPTS)
    {
        fprintf(stderr, "at most %d SQL scripts are allowed\n", MAX_SCRIPTS);
        exit(1);
    }

    sql_script[num_scripts] = script;
    num_scripts++;
}

static void
printSimpleStats(char *prefix, SimpleStats *ss)
{
    /* print NaN if no transactions where executed */
    double      latency = ss->sum / ss->count;
    double      stddev = sqrt(ss->sum2 / ss->count - latency * latency);

    printf("%s average = %.3f ms\n", prefix, 0.001 * latency);
    printf("%s stddev = %.3f ms\n", prefix, 0.001 * stddev);
}

/* print out results */
static void
printResults(TState *threads, StatsData *total, instr_time total_time,
             instr_time conn_total_time, int latency_late)
{
    double      time_include,
                tps_include,
                tps_exclude;

    time_include = INSTR_TIME_GET_DOUBLE(total_time);
    tps_include = total->cnt / time_include;
    tps_exclude = total->cnt / (time_include -
                                (INSTR_TIME_GET_DOUBLE(conn_total_time) / nclients));

    /* Report test parameters. */
    printf("transaction type: %s\n",
           num_scripts == 1 ? sql_script[0].desc : "multiple scripts");
    printf("scaling factor: %d\n", scale);
    printf("query mode: %s\n", QUERYMODE[querymode]);
    printf("number of clients: %d\n", nclients);
    printf("number of threads: %d\n", nthreads);
    if (duration <= 0)
    {
        printf("number of transactions per client: %d\n", nxacts);
        printf("number of transactions actually processed: " INT64_FORMAT "/%d\n",
               total->cnt - total->skipped, nxacts * nclients);
    }
    else
    {
        printf("duration: %d s\n", duration);
        printf("number of transactions actually processed: " INT64_FORMAT "\n",
               total->cnt);
    }

    /* Remaining stats are nonsensical if we failed to execute any xacts */
    if (total->cnt <= 0)
        return;

    if (throttle_delay && latency_limit)
        printf("number of transactions skipped: " INT64_FORMAT " (%.3f %%)\n",
               total->skipped,
               100.0 * total->skipped / total->cnt);

    if (latency_limit)
        printf("number of transactions above the %.1f ms latency limit: %d (%.3f %%)\n",
               latency_limit / 1000.0, latency_late,
               100.0 * latency_late / total->cnt);

    if (throttle_delay || progress || latency_limit)
        printSimpleStats("latency", &total->latency);
    else
    {
        /* no measurement, show average latency computed from run time */
        printf("latency average = %.3f ms\n",
               1000.0 * time_include * nclients / total->cnt);
    }

    if (throttle_delay)
    {
        /*
         * Report average transaction lag under rate limit throttling.  This
         * is the delay between scheduled and actual start times for the
         * transaction.  The measured lag may be caused by thread/client load,
         * the database load, or the Poisson throttling process.
         */
        printf("rate limit schedule lag: avg %.3f (max %.3f) ms\n",
               0.001 * total->lag.sum / total->cnt, 0.001 * total->lag.max);
    }

    printf("tps = %f (including connections establishing)\n", tps_include);
    printf("tps = %f (excluding connections establishing)\n", tps_exclude);

    /* Report per-script/command statistics */
    if (per_script_stats || latency_limit || is_latencies)
    {
        int         i;

        for (i = 0; i < num_scripts; i++)
        {
            if (num_scripts > 1)
                printf("SQL script %d: %s\n"
                       " - weight: %d (targets %.1f%% of total)\n"
                       " - " INT64_FORMAT " transactions (%.1f%% of total, tps = %f)\n",
                       i + 1, sql_script[i].desc,
                       sql_script[i].weight,
                       100.0 * sql_script[i].weight / total_weight,
                       sql_script[i].stats.cnt,
                       100.0 * sql_script[i].stats.cnt / total->cnt,
                       sql_script[i].stats.cnt / time_include);
            else
                printf("script statistics:\n");

            if (latency_limit)
                printf(" - number of transactions skipped: " INT64_FORMAT " (%.3f%%)\n",
                       sql_script[i].stats.skipped,
                       100.0 * sql_script[i].stats.skipped / sql_script[i].stats.cnt);

            if (num_scripts > 1)
                printSimpleStats(" - latency", &sql_script[i].stats.latency);

            /* Report per-command latencies */
            if (is_latencies)
            {
                Command   **commands;

                printf(" - statement latencies in milliseconds:\n");

                for (commands = sql_script[i].commands;
                     *commands != NULL;
                     commands++)
                    printf("   %11.3f  %s\n",
                           1000.0 * (*commands)->stats.sum /
                           (*commands)->stats.count,
                           (*commands)->line);
            }
        }
    }
}


int
main(int argc, char **argv)
{
    static struct option long_options[] = {
        /* systematic long/short named options */
        {"builtin", required_argument, NULL, 'b'},
        {"client", required_argument, NULL, 'c'},
        {"connect", no_argument, NULL, 'C'},
        {"debug", no_argument, NULL, 'd'},
        {"define", required_argument, NULL, 'D'},
        {"file", required_argument, NULL, 'f'},
        {"fillfactor", required_argument, NULL, 'F'},
        {"host", required_argument, NULL, 'h'},
        {"initialize", no_argument, NULL, 'i'},
        {"jobs", required_argument, NULL, 'j'},
        {"log", no_argument, NULL, 'l'},
        {"latency-limit", required_argument, NULL, 'L'},
        {"no-vacuum", no_argument, NULL, 'n'},
        {"port", required_argument, NULL, 'p'},
        {"progress", required_argument, NULL, 'P'},
        {"protocol", required_argument, NULL, 'M'},
        {"quiet", no_argument, NULL, 'q'},
        {"report-latencies", no_argument, NULL, 'r'},
        {"rate", required_argument, NULL, 'R'},
        {"scale", required_argument, NULL, 's'},
        {"select-only", no_argument, NULL, 'S'},
        {"skip-some-updates", no_argument, NULL, 'N'},
        {"time", required_argument, NULL, 'T'},
        {"transactions", required_argument, NULL, 't'},
        {"username", required_argument, NULL, 'U'},
        {"vacuum-all", no_argument, NULL, 'v'},
        /* long-named only options */
        {"foreign-keys", no_argument, &foreign_keys, 1},
        {"index-tablespace", required_argument, NULL, 3},
        {"tablespace", required_argument, NULL, 2},
        {"unlogged-tables", no_argument, &unlogged_tables, 1},
        {"sampling-rate", required_argument, NULL, 4},
        {"aggregate-interval", required_argument, NULL, 5},
        {"progress-timestamp", no_argument, NULL, 6},
        {"log-prefix", required_argument, NULL, 7},
        {NULL, 0, NULL, 0}
    };

    int         c;
    int         is_init_mode = 0;   /* initialize mode? */
    int         is_no_vacuum = 0;   /* no vacuum at all before testing? */
    int         do_vacuum_accounts = 0; /* do vacuum accounts before testing? */
    int         optindex;
    bool        scale_given = false;

    bool        benchmarking_option_set = false;
    bool        initialization_option_set = false;
    bool        internal_script_used = false;

    CState     *state;          /* status of clients */
    TState     *threads;        /* array of thread */

    instr_time  start_time;     /* start up time */
    instr_time  total_time;
    instr_time  conn_total_time;
    int64       latency_late = 0;
    StatsData   stats;
    int         weight;

    int         i;
    int         nclients_dealt;

#ifdef HAVE_GETRLIMIT
    struct rlimit rlim;
#endif

    PGconn     *con;
    PGresult   *res;
    char       *env;

    progname = get_progname(argv[0]);

    if (argc > 1)
    {
        if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
        {
            usage();
            exit(0);
        }
        if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
        {
            puts("pgbench (PostgreSQL) " PG_VERSION);
            exit(0);
        }
    }

#ifdef WIN32
    /* stderr is buffered on Win32. */
    setvbuf(stderr, NULL, _IONBF, 0);
#endif

    if ((env = getenv("PGHOST")) != NULL && *env != '\0')
        pghost = env;
    if ((env = getenv("PGPORT")) != NULL && *env != '\0')
        pgport = env;
    else if ((env = getenv("PGUSER")) != NULL && *env != '\0')
        login = env;

    state = (CState *) pg_malloc(sizeof(CState));
    memset(state, 0, sizeof(CState));

    while ((c = getopt_long(argc, argv, "ih:nvp:dqb:SNc:j:Crs:t:T:U:lf:D:F:M:P:R:L:", long_options, &optindex)) != -1)
    {
        char       *script;

        switch (c)
        {
            case 'i':
                is_init_mode++;
                break;
            case 'h':
                pghost = pg_strdup(optarg);
                break;
            case 'n':
                is_no_vacuum++;
                break;
            case 'v':
                do_vacuum_accounts++;
                break;
            case 'p':
                pgport = pg_strdup(optarg);
                break;
            case 'd':
                debug++;
                break;
            case 'c':
                benchmarking_option_set = true;
                nclients = atoi(optarg);
                if (nclients <= 0 || nclients > MAXCLIENTS)
                {
                    fprintf(stderr, "invalid number of clients: \"%s\"\n",
                            optarg);
                    exit(1);
                }
#ifdef HAVE_GETRLIMIT
#ifdef RLIMIT_NOFILE            /* most platforms use RLIMIT_NOFILE */
                if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
#else                           /* but BSD doesn't ... */
                if (getrlimit(RLIMIT_OFILE, &rlim) == -1)
#endif                          /* RLIMIT_NOFILE */
                {
                    fprintf(stderr, "getrlimit failed: %s\n", strerror(errno));
                    exit(1);
                }
                if (rlim.rlim_cur < nclients + 3)
                {
                    fprintf(stderr, "need at least %d open files, but system limit is %ld\n",
                            nclients + 3, (long) rlim.rlim_cur);
                    fprintf(stderr, "Reduce number of clients, or use limit/ulimit to increase the system limit.\n");
                    exit(1);
                }
#endif                          /* HAVE_GETRLIMIT */
                break;
            case 'j':           /* jobs */
                benchmarking_option_set = true;
                nthreads = atoi(optarg);
                if (nthreads <= 0)
                {
                    fprintf(stderr, "invalid number of threads: \"%s\"\n",
                            optarg);
                    exit(1);
                }
#ifndef ENABLE_THREAD_SAFETY
                if (nthreads != 1)
                {
                    fprintf(stderr, "threads are not supported on this platform; use -j1\n");
                    exit(1);
                }
#endif                          /* !ENABLE_THREAD_SAFETY */
                break;
            case 'C':
                benchmarking_option_set = true;
                is_connect = true;
                break;
            case 'r':
                benchmarking_option_set = true;
                per_script_stats = true;
                is_latencies = true;
                break;
            case 's':
                scale_given = true;
                scale = atoi(optarg);
                if (scale <= 0)
                {
                    fprintf(stderr, "invalid scaling factor: \"%s\"\n", optarg);
                    exit(1);
                }
                break;
            case 't':
                benchmarking_option_set = true;
                if (duration > 0)
                {
                    fprintf(stderr, "specify either a number of transactions (-t) or a duration (-T), not both\n");
                    exit(1);
                }
                nxacts = atoi(optarg);
                if (nxacts <= 0)
                {
                    fprintf(stderr, "invalid number of transactions: \"%s\"\n",
                            optarg);
                    exit(1);
                }
                break;
            case 'T':
                benchmarking_option_set = true;
                if (nxacts > 0)
                {
                    fprintf(stderr, "specify either a number of transactions (-t) or a duration (-T), not both\n");
                    exit(1);
                }
                duration = atoi(optarg);
                if (duration <= 0)
                {
                    fprintf(stderr, "invalid duration: \"%s\"\n", optarg);
                    exit(1);
                }
                break;
            case 'U':
                login = pg_strdup(optarg);
                break;
            case 'l':
                benchmarking_option_set = true;
                use_log = true;
                break;
            case 'q':
                initialization_option_set = true;
                use_quiet = true;
                break;

            case 'b':
                if (strcmp(optarg, "list") == 0)
                {
                    listAvailableScripts();
                    exit(0);
                }

                weight = parseScriptWeight(optarg, &script);
                process_builtin(findBuiltin(script), weight);
                benchmarking_option_set = true;
                internal_script_used = true;
                break;

            case 'S':
                process_builtin(findBuiltin("select-only"), 1);
                benchmarking_option_set = true;
                internal_script_used = true;
                break;
            case 'N':
                process_builtin(findBuiltin("simple-update"), 1);
                benchmarking_option_set = true;
                internal_script_used = true;
                break;
            case 'f':
                weight = parseScriptWeight(optarg, &script);
                process_file(script, weight);
                benchmarking_option_set = true;
                break;
            case 'D':
                {
                    char       *p;

                    benchmarking_option_set = true;

                    if ((p = strchr(optarg, '=')) == NULL || p == optarg || *(p + 1) == '\0')
                    {
                        fprintf(stderr, "invalid variable definition: \"%s\"\n",
                                optarg);
                        exit(1);
                    }

                    *p++ = '\0';
                    if (!putVariable(&state[0], "option", optarg, p))
                        exit(1);
                }
                break;
            case 'F':
                initialization_option_set = true;
                fillfactor = atoi(optarg);
                if (fillfactor < 10 || fillfactor > 100)
                {
                    fprintf(stderr, "invalid fillfactor: \"%s\"\n", optarg);
                    exit(1);
                }
                break;
            case 'M':
                benchmarking_option_set = true;
                for (querymode = 0; querymode < NUM_QUERYMODE; querymode++)
                    if (strcmp(optarg, QUERYMODE[querymode]) == 0)
                        break;
                if (querymode >= NUM_QUERYMODE)
                {
                    fprintf(stderr, "invalid query mode (-M): \"%s\"\n",
                            optarg);
                    exit(1);
                }
                break;
            case 'P':
                benchmarking_option_set = true;
                progress = atoi(optarg);
                if (progress <= 0)
                {
                    fprintf(stderr, "invalid thread progress delay: \"%s\"\n",
                            optarg);
                    exit(1);
                }
                break;
            case 'R':
                {
                    /* get a double from the beginning of option value */
                    double      throttle_value = atof(optarg);

                    benchmarking_option_set = true;

                    if (throttle_value <= 0.0)
                    {
                        fprintf(stderr, "invalid rate limit: \"%s\"\n", optarg);
                        exit(1);
                    }
                    /* Invert rate limit into a time offset */
                    throttle_delay = (int64) (1000000.0 / throttle_value);
                }
                break;
            case 'L':
                {
                    double      limit_ms = atof(optarg);

                    if (limit_ms <= 0.0)
                    {
                        fprintf(stderr, "invalid latency limit: \"%s\"\n",
                                optarg);
                        exit(1);
                    }
                    benchmarking_option_set = true;
                    latency_limit = (int64) (limit_ms * 1000);
                }
                break;
            case 0:
                /* This covers long options which take no argument. */
                if (foreign_keys || unlogged_tables)
                    initialization_option_set = true;
                break;
            case 2:             /* tablespace */
                initialization_option_set = true;
                tablespace = pg_strdup(optarg);
                break;
            case 3:             /* index-tablespace */
                initialization_option_set = true;
                index_tablespace = pg_strdup(optarg);
                break;
            case 4:
                benchmarking_option_set = true;
                sample_rate = atof(optarg);
                if (sample_rate <= 0.0 || sample_rate > 1.0)
                {
                    fprintf(stderr, "invalid sampling rate: \"%s\"\n", optarg);
                    exit(1);
                }
                break;
            case 5:
                benchmarking_option_set = true;
                agg_interval = atoi(optarg);
                if (agg_interval <= 0)
                {
                    fprintf(stderr, "invalid number of seconds for aggregation: \"%s\"\n",
                            optarg);
                    exit(1);
                }
                break;
            case 6:
                progress_timestamp = true;
                benchmarking_option_set = true;
                break;
            case 7:
                benchmarking_option_set = true;
                logfile_prefix = pg_strdup(optarg);
                break;
            default:
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
                exit(1);
                break;
        }
    }

    /* set default script if none */
    if (num_scripts == 0 && !is_init_mode)
    {
        process_builtin(findBuiltin("tpcb-like"), 1);
        benchmarking_option_set = true;
        internal_script_used = true;
    }

    /* if not simple query mode, parse the script(s) to find parameters */
    if (querymode != QUERY_SIMPLE)
    {
        for (i = 0; i < num_scripts; i++)
        {
            Command   **commands = sql_script[i].commands;
            int         j;

            for (j = 0; commands[j] != NULL; j++)
            {
                if (commands[j]->type != SQL_COMMAND)
                    continue;
                if (!parseQuery(commands[j]))
                    exit(1);
            }
        }
    }

    /* compute total_weight */
    for (i = 0; i < num_scripts; i++)
        /* cannot overflow: weight is 32b, total_weight 64b */
        total_weight += sql_script[i].weight;

    if (total_weight == 0 && !is_init_mode)
    {
        fprintf(stderr, "total script weight must not be zero\n");
        exit(1);
    }

    /* show per script stats if several scripts are used */
    if (num_scripts > 1)
        per_script_stats = true;

    /*
     * Don't need more threads than there are clients.  (This is not merely an
     * optimization; throttle_delay is calculated incorrectly below if some
     * threads have no clients assigned to them.)
     */
    if (nthreads > nclients)
        nthreads = nclients;

    /* compute a per thread delay */
    throttle_delay *= nthreads;

    if (argc > optind)
        dbName = argv[optind];
    else
    {
        if ((env = getenv("PGDATABASE")) != NULL && *env != '\0')
            dbName = env;
        else if (login != NULL && *login != '\0')
            dbName = login;
        else
            dbName = "";
    }

    if (is_init_mode)
    {
        if (benchmarking_option_set)
        {
            fprintf(stderr, "some of the specified options cannot be used in initialization (-i) mode\n");
            exit(1);
        }

        init(is_no_vacuum);
        exit(0);
    }
    else
    {
        if (initialization_option_set)
        {
            fprintf(stderr, "some of the specified options cannot be used in benchmarking mode\n");
            exit(1);
        }
    }

    /* Use DEFAULT_NXACTS if neither nxacts nor duration is specified. */
    if (nxacts <= 0 && duration <= 0)
        nxacts = DEFAULT_NXACTS;

    /* --sampling-rate may be used only with -l */
    if (sample_rate > 0.0 && !use_log)
    {
        fprintf(stderr, "log sampling (--sampling-rate) is allowed only when logging transactions (-l)\n");
        exit(1);
    }

    /* --sampling-rate may not be used with --aggregate-interval */
    if (sample_rate > 0.0 && agg_interval > 0)
    {
        fprintf(stderr, "log sampling (--sampling-rate) and aggregation (--aggregate-interval) cannot be used at the same time\n");
        exit(1);
    }

    if (agg_interval > 0 && !use_log)
    {
        fprintf(stderr, "log aggregation is allowed only when actually logging transactions\n");
        exit(1);
    }

    if (!use_log && logfile_prefix)
    {
        fprintf(stderr, "log file prefix (--log-prefix) is allowed only when logging transactions (-l)\n");
        exit(1);
    }

    if (duration > 0 && agg_interval > duration)
    {
        fprintf(stderr, "number of seconds for aggregation (%d) must not be higher than test duration (%d)\n", agg_interval, duration);
        exit(1);
    }

    if (duration > 0 && agg_interval > 0 && duration % agg_interval != 0)
    {
        fprintf(stderr, "duration (%d) must be a multiple of aggregation interval (%d)\n", duration, agg_interval);
        exit(1);
    }

    if (progress_timestamp && progress == 0)
    {
        fprintf(stderr, "--progress-timestamp is allowed only under --progress\n");
        exit(1);
    }

    /*
     * save main process id in the global variable because process id will be
     * changed after fork.
     */
    main_pid = (int) getpid();

    if (nclients > 1)
    {
        state = (CState *) pg_realloc(state, sizeof(CState) * nclients);
        memset(state + 1, 0, sizeof(CState) * (nclients - 1));

        /* copy any -D switch values to all clients */
        for (i = 1; i < nclients; i++)
        {
            int         j;

            state[i].id = i;
            for (j = 0; j < state[0].nvariables; j++)
            {
                Variable   *var = &state[0].variables[j];

                if (var->is_numeric)
                {
                    if (!putVariableNumber(&state[i], "startup",
                                           var->name, &var->num_value))
                        exit(1);
                }
                else
                {
                    if (!putVariable(&state[i], "startup",
                                     var->name, var->value))
                        exit(1);
                }
            }
        }
    }

    if (debug)
    {
        if (duration <= 0)
            printf("pghost: %s pgport: %s nclients: %d nxacts: %d dbName: %s\n",
                   pghost, pgport, nclients, nxacts, dbName);
        else
            printf("pghost: %s pgport: %s nclients: %d duration: %d dbName: %s\n",
                   pghost, pgport, nclients, duration, dbName);
    }

    /* opening connection... */
    con = doConnect();
    if (con == NULL)
        exit(1);

    if (PQstatus(con) == CONNECTION_BAD)
    {
        fprintf(stderr, "connection to database \"%s\" failed\n", dbName);
        fprintf(stderr, "%s", PQerrorMessage(con));
        exit(1);
    }

    if (internal_script_used)
    {
        /*
         * 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);

            fprintf(stderr, "%s", PQerrorMessage(con));
            if (sqlState && strcmp(sqlState, ERRCODE_UNDEFINED_TABLE) == 0)
            {
                fprintf(stderr, "Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\"\n", PQdb(con));
            }

            exit(1);
        }
        scale = atoi(PQgetvalue(res, 0, 0));
        if (scale < 0)
        {
            fprintf(stderr, "invalid count(*) from pgbench_branches: \"%s\"\n",
                    PQgetvalue(res, 0, 0));
            exit(1);
        }
        PQclear(res);

        /* warn if we override user-given -s switch */
        if (scale_given)
            fprintf(stderr,
                    "scale option ignored, using count from pgbench_branches table (%d)\n",
                    scale);
    }

    /*
     * :scale variables normally get -s or database scale, but don't override
     * an explicit -D switch
     */
    if (lookupVariable(&state[0], "scale") == NULL)
    {
        for (i = 0; i < nclients; i++)
        {
            if (!putVariableInt(&state[i], "startup", "scale", scale))
                exit(1);
        }
    }

    /*
     * Define a :client_id variable that is unique per connection. But don't
     * override an explicit -D switch.
     */
    if (lookupVariable(&state[0], "client_id") == NULL)
    {
        for (i = 0; i < nclients; i++)
        {
            if (!putVariableInt(&state[i], "startup", "client_id", i))
                exit(1);
        }
    }

    if (!is_no_vacuum)
    {
        fprintf(stderr, "starting vacuum...");
        tryExecuteStatement(con, "vacuum pgbench_branches");
        tryExecuteStatement(con, "vacuum pgbench_tellers");
        tryExecuteStatement(con, "truncate pgbench_history");
        fprintf(stderr, "end.\n");

        if (do_vacuum_accounts)
        {
            fprintf(stderr, "starting vacuum pgbench_accounts...");
            tryExecuteStatement(con, "vacuum analyze pgbench_accounts");
            fprintf(stderr, "end.\n");
        }
    }
    PQfinish(con);

    /* set random seed */
    INSTR_TIME_SET_CURRENT(start_time);
    srandom((unsigned int) INSTR_TIME_GET_MICROSEC(start_time));

    /* set up thread data structures */
    threads = (TState *) pg_malloc(sizeof(TState) * nthreads);
    nclients_dealt = 0;

    for (i = 0; i < nthreads; i++)
    {
        TState     *thread = &threads[i];

        thread->tid = i;
        thread->state = &state[nclients_dealt];
        thread->nstate =
            (nclients - nclients_dealt + nthreads - i - 1) / (nthreads - i);
        thread->random_state[0] = random();
        thread->random_state[1] = random();
        thread->random_state[2] = random();
        thread->logfile = NULL; /* filled in later */
        thread->latency_late = 0;
        initStats(&thread->stats, 0);

        nclients_dealt += thread->nstate;
    }

    /* all clients must be assigned to a thread */
    Assert(nclients_dealt == nclients);

    /* get start up time */
    INSTR_TIME_SET_CURRENT(start_time);

    /* set alarm if duration is specified. */
    if (duration > 0)
        setalarm(duration);

    /* start threads */
#ifdef ENABLE_THREAD_SAFETY
    for (i = 0; i < nthreads; i++)
    {
        TState     *thread = &threads[i];

        INSTR_TIME_SET_CURRENT(thread->start_time);

        /* compute when to stop */
        if (duration > 0)
            end_time = INSTR_TIME_GET_MICROSEC(thread->start_time) +
                (int64) 1000000 * duration;

        /* the first thread (i = 0) is executed by main thread */
        if (i > 0)
        {
            int         err = pthread_create(&thread->thread, NULL, threadRun, thread);

            if (err != 0 || thread->thread == INVALID_THREAD)
            {
                fprintf(stderr, "could not create thread: %s\n", strerror(err));
                exit(1);
            }
        }
        else
        {
            thread->thread = INVALID_THREAD;
        }
    }
#else
    INSTR_TIME_SET_CURRENT(threads[0].start_time);
    /* compute when to stop */
    if (duration > 0)
        end_time = INSTR_TIME_GET_MICROSEC(threads[0].start_time) +
            (int64) 1000000 * duration;
    threads[0].thread = INVALID_THREAD;
#endif                          /* ENABLE_THREAD_SAFETY */

    /* wait for threads and accumulate results */
    initStats(&stats, 0);
    INSTR_TIME_SET_ZERO(conn_total_time);
    for (i = 0; i < nthreads; i++)
    {
        TState     *thread = &threads[i];

#ifdef ENABLE_THREAD_SAFETY
        if (threads[i].thread == INVALID_THREAD)
            /* actually run this thread directly in the main thread */
            (void) threadRun(thread);
        else
            /* wait of other threads. should check that 0 is returned? */
            pthread_join(thread->thread, NULL);
#else
        (void) threadRun(thread);
#endif                          /* ENABLE_THREAD_SAFETY */

        /* aggregate thread level stats */
        mergeSimpleStats(&stats.latency, &thread->stats.latency);
        mergeSimpleStats(&stats.lag, &thread->stats.lag);
        stats.cnt += thread->stats.cnt;
        stats.skipped += thread->stats.skipped;
        latency_late += thread->latency_late;
        INSTR_TIME_ADD(conn_total_time, thread->conn_time);
    }
    disconnect_all(state, nclients);

    /*
     * XXX We compute results as though every client of every thread started
     * and finished at the same time.  That model can diverge noticeably from
     * reality for a short benchmark run involving relatively many threads.
     * The first thread may process notably many transactions before the last
     * thread begins.  Improving the model alone would bring limited benefit,
     * because performance during those periods of partial thread count can
     * easily exceed steady state performance.  This is one of the many ways
     * short runs convey deceptive performance figures.
     */
    INSTR_TIME_SET_CURRENT(total_time);
    INSTR_TIME_SUBTRACT(total_time, start_time);
    printResults(threads, &stats, total_time, conn_total_time, latency_late);

    return 0;
}

static void *
threadRun(void *arg)
{
    TState     *thread = (TState *) arg;
    CState     *state = thread->state;
    instr_time  start,
                end;
    int         nstate = thread->nstate;
    int         remains = nstate;   /* number of remaining clients */
    int         i;

    /* for reporting progress: */
    int64       thread_start = INSTR_TIME_GET_MICROSEC(thread->start_time);
    int64       last_report = thread_start;
    int64       next_report = last_report + (int64) progress * 1000000;
    StatsData   last,
                aggs;

    /*
     * Initialize throttling rate target for all of the thread's clients.  It
     * might be a little more accurate to reset thread->start_time here too.
     * The possible drift seems too small relative to typical throttle delay
     * times to worry about it.
     */
    INSTR_TIME_SET_CURRENT(start);
    thread->throttle_trigger = INSTR_TIME_GET_MICROSEC(start);

    INSTR_TIME_SET_ZERO(thread->conn_time);

    initStats(&aggs, time(NULL));
    last = aggs;

    /* open log file if requested */
    if (use_log)
    {
        char        logpath[MAXPGPATH];
        char       *prefix = logfile_prefix ? logfile_prefix : "pgbench_log";

        if (thread->tid == 0)
            snprintf(logpath, sizeof(logpath), "%s.%d", prefix, main_pid);
        else
            snprintf(logpath, sizeof(logpath), "%s.%d.%d", prefix, main_pid, thread->tid);

        thread->logfile = fopen(logpath, "w");

        if (thread->logfile == NULL)
        {
            fprintf(stderr, "could not open logfile \"%s\": %s\n",
                    logpath, strerror(errno));
            goto done;
        }
    }

    if (!is_connect)
    {
        /* make connections to the database */
        for (i = 0; i < nstate; i++)
        {
            if ((state[i].con = doConnect()) == NULL)
                goto done;
        }
    }

    /* time after thread and connections set up */
    INSTR_TIME_SET_CURRENT(thread->conn_time);
    INSTR_TIME_SUBTRACT(thread->conn_time, thread->start_time);

    /* explicitly initialize the state machines */
    for (i = 0; i < nstate; i++)
    {
        state[i].state = CSTATE_CHOOSE_SCRIPT;
    }

    /* loop till all clients have terminated */
    while (remains > 0)
    {
        fd_set      input_mask;
        int         maxsock;    /* max socket number to be waited for */
        int64       min_usec;
        int64       now_usec = 0;   /* set this only if needed */

        /* identify which client sockets should be checked for input */
        FD_ZERO(&input_mask);
        maxsock = -1;
        min_usec = PG_INT64_MAX;
        for (i = 0; i < nstate; i++)
        {
            CState     *st = &state[i];

            if (st->state == CSTATE_THROTTLE && timer_exceeded)
            {
                /* interrupt client that has not started a transaction */
                st->state = CSTATE_FINISHED;
                PQfinish(st->con);
                st->con = NULL;
                remains--;
            }
            else if (st->state == CSTATE_SLEEP || st->state == CSTATE_THROTTLE)
            {
                /* a nap from the script, or under throttling */
                int64       this_usec;

                /* get current time if needed */
                if (now_usec == 0)
                {
                    instr_time  now;

                    INSTR_TIME_SET_CURRENT(now);
                    now_usec = INSTR_TIME_GET_MICROSEC(now);
                }

                /* min_usec should be the minimum delay across all clients */
                this_usec = (st->state == CSTATE_SLEEP ?
                             st->sleep_until : st->txn_scheduled) - now_usec;
                if (min_usec > this_usec)
                    min_usec = this_usec;
            }
            else if (st->state == CSTATE_WAIT_RESULT)
            {
                /*
                 * waiting for result from server - nothing to do unless the
                 * socket is readable
                 */
                int         sock = PQsocket(st->con);

                if (sock < 0)
                {
                    fprintf(stderr, "invalid socket: %s",
                            PQerrorMessage(st->con));
                    goto done;
                }

                FD_SET(sock, &input_mask);
                if (maxsock < sock)
                    maxsock = sock;
            }
            else if (st->state != CSTATE_ABORTED &&
                     st->state != CSTATE_FINISHED)
            {
                /*
                 * This client thread is ready to do something, so we don't
                 * want to wait.  No need to examine additional clients.
                 */
                min_usec = 0;
                break;
            }
        }

        /* also wake up to print the next progress report on time */
        if (progress && min_usec > 0 && thread->tid == 0)
        {
            /* get current time if needed */
            if (now_usec == 0)
            {
                instr_time  now;

                INSTR_TIME_SET_CURRENT(now);
                now_usec = INSTR_TIME_GET_MICROSEC(now);
            }

            if (now_usec >= next_report)
                min_usec = 0;
            else if ((next_report - now_usec) < min_usec)
                min_usec = next_report - now_usec;
        }

        /*
         * If no clients are ready to execute actions, sleep until we receive
         * data from the server, or a nap-time specified in the script ends,
         * or it's time to print a progress report.  Update input_mask to show
         * which client(s) received data.
         */
        if (min_usec > 0)
        {
            int         nsocks = 0; /* return from select(2) if called */

            if (min_usec != PG_INT64_MAX)
            {
                if (maxsock != -1)
                {
                    struct timeval timeout;

                    timeout.tv_sec = min_usec / 1000000;
                    timeout.tv_usec = min_usec % 1000000;
                    nsocks = select(maxsock + 1, &input_mask, NULL, NULL, &timeout);
                }
                else /* nothing active, simple sleep */
                {
                    pg_usleep(min_usec);
                }
            }
            else /* no explicit delay, select without timeout */
            {
                nsocks = select(maxsock + 1, &input_mask, NULL, NULL, NULL);
            }

            if (nsocks < 0)
            {
                if (errno == EINTR)
                {
                    /* On EINTR, go back to top of loop */
                    continue;
                }
                /* must be something wrong */
                fprintf(stderr, "select() failed: %s\n", strerror(errno));
                goto done;
            }
        }
        else /* min_usec == 0, i.e. something needs to be executed */
        {
            /* If we didn't call select(), don't try to read any data */
            FD_ZERO(&input_mask);
        }

        /* ok, advance the state machine of each connection */
        for (i = 0; i < nstate; i++)
        {
            CState     *st = &state[i];

            if (st->state == CSTATE_WAIT_RESULT)
            {
                /* don't call doCustom unless data is available */
                int         sock = PQsocket(st->con);

                if (sock < 0)
                {
                    fprintf(stderr, "invalid socket: %s",
                            PQerrorMessage(st->con));
                    goto done;
                }

                if (!FD_ISSET(sock, &input_mask))
                    continue;
            }
            else if (st->state == CSTATE_FINISHED ||
                     st->state == CSTATE_ABORTED)
            {
                /* this client is done, no need to consider it anymore */
                continue;
            }

            doCustom(thread, st, &aggs);

            /* If doCustom changed client to finished state, reduce remains */
            if (st->state == CSTATE_FINISHED || st->state == CSTATE_ABORTED)
                remains--;
        }

        /* progress report is made by thread 0 for all threads */
        if (progress && thread->tid == 0)
        {
            instr_time  now_time;
            int64       now;

            INSTR_TIME_SET_CURRENT(now_time);
            now = INSTR_TIME_GET_MICROSEC(now_time);
            if (now >= next_report)
            {
                /* generate and show report */
                StatsData   cur;
                int64       run = now - last_report;
                double      tps,
                            total_run,
                            latency,
                            sqlat,
                            lag,
                            stdev;
                char        tbuf[64];

                /*
                 * Add up the statistics of all threads.
                 *
                 * XXX: No locking. There is no guarantee that we get an
                 * atomic snapshot of the transaction count and latencies, so
                 * these figures can well be off by a small amount. The
                 * progress is report's purpose is to give a quick overview of
                 * how the test is going, so that shouldn't matter too much.
                 * (If a read from a 64-bit integer is not atomic, you might
                 * get a "torn" read and completely bogus latencies though!)
                 */
                initStats(&cur, 0);
                for (i = 0; i < nthreads; i++)
                {
                    mergeSimpleStats(&cur.latency, &thread[i].stats.latency);
                    mergeSimpleStats(&cur.lag, &thread[i].stats.lag);
                    cur.cnt += thread[i].stats.cnt;
                    cur.skipped += thread[i].stats.skipped;
                }

                total_run = (now - thread_start) / 1000000.0;
                tps = 1000000.0 * (cur.cnt - last.cnt) / run;
                latency = 0.001 * (cur.latency.sum - last.latency.sum) /
                    (cur.cnt - last.cnt);
                sqlat = 1.0 * (cur.latency.sum2 - last.latency.sum2)
                    / (cur.cnt - last.cnt);
                stdev = 0.001 * sqrt(sqlat - 1000000.0 * latency * latency);
                lag = 0.001 * (cur.lag.sum - last.lag.sum) /
                    (cur.cnt - last.cnt);

                if (progress_timestamp)
                {
                    /*
                     * On some platforms the current system timestamp is
                     * available in now_time, but rather than get entangled
                     * with that, we just eat the cost of an extra syscall in
                     * all cases.
                     */
                    struct timeval tv;

                    gettimeofday(&tv, NULL);
                    snprintf(tbuf, sizeof(tbuf), "%ld.%03ld s",
                             (long) tv.tv_sec, (long) (tv.tv_usec / 1000));
                }
                else
                    snprintf(tbuf, sizeof(tbuf), "%.1f s", total_run);

                fprintf(stderr,
                        "progress: %s, %.1f tps, lat %.3f ms stddev %.3f",
                        tbuf, tps, latency, stdev);

                if (throttle_delay)
                {
                    fprintf(stderr, ", lag %.3f ms", lag);
                    if (latency_limit)
                        fprintf(stderr, ", " INT64_FORMAT " skipped",
                                cur.skipped - last.skipped);
                }
                fprintf(stderr, "\n");

                last = cur;
                last_report = now;

                /*
                 * Ensure that the next report is in the future, in case
                 * pgbench/postgres got stuck somewhere.
                 */
                do
                {
                    next_report += (int64) progress * 1000000;
                } while (now >= next_report);
            }
        }
    }

done:
    INSTR_TIME_SET_CURRENT(start);
    disconnect_all(state, nstate);
    INSTR_TIME_SET_CURRENT(end);
    INSTR_TIME_ACCUM_DIFF(thread->conn_time, end, start);
    if (thread->logfile)
    {
        if (agg_interval > 0)
        {
            /* log aggregated but not yet reported transactions */
            doLog(thread, state, &aggs, false, 0, 0);
        }
        fclose(thread->logfile);
        thread->logfile = NULL;
    }
    return NULL;
}

/*
 * Support for duration option: set timer_exceeded after so many seconds.
 */

#ifndef WIN32

static void
handle_sig_alarm(SIGNAL_ARGS)
{
    timer_exceeded = true;
}

static void
setalarm(int seconds)
{
    pqsignal(SIGALRM, handle_sig_alarm);
    alarm(seconds);
}

#else                           /* WIN32 */

static VOID CALLBACK
win32_timer_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
{
    timer_exceeded = true;
}

static void
setalarm(int seconds)
{
    HANDLE      queue;
    HANDLE      timer;

    /* This function will be called at most once, so we can cheat a bit. */
    queue = CreateTimerQueue();
    if (seconds > ((DWORD) -1) / 1000 ||
        !CreateTimerQueueTimer(&timer, queue,
                               win32_timer_callback, NULL, seconds * 1000, 0,
                               WT_EXECUTEINTIMERTHREAD | WT_EXECUTEONLYONCE))
    {
        fprintf(stderr, "failed to set timer\n");
        exit(1);
    }
}

/* partial pthread implementation for Windows */

typedef struct win32_pthread
{
    HANDLE      handle;
    void       *(*routine) (void *);
    void       *arg;
    void       *result;
} win32_pthread;

static unsigned __stdcall
win32_pthread_run(void *arg)
{
    win32_pthread *th = (win32_pthread *) arg;

    th->result = th->routine(th->arg);

    return 0;
}

static int
pthread_create(pthread_t *thread,
               pthread_attr_t *attr,
               void *(*start_routine) (void *),
               void *arg)
{
    int         save_errno;
    win32_pthread *th;

    th = (win32_pthread *) pg_malloc(sizeof(win32_pthread));
    th->routine = start_routine;
    th->arg = arg;
    th->result = NULL;

    th->handle = (HANDLE) _beginthreadex(NULL, 0, win32_pthread_run, th, 0, NULL);
    if (th->handle == NULL)
    {
        save_errno = errno;
        free(th);
        return save_errno;
    }

    *thread = th;
    return 0;
}

static int
pthread_join(pthread_t th, void **thread_return)
{
    if (th == NULL || th->handle == NULL)
        return errno = EINVAL;

    if (WaitForSingleObject(th->handle, INFINITE) != WAIT_OBJECT_0)
    {
        _dosmaperr(GetLastError());
        return errno;
    }

    if (thread_return)
        *thread_return = th->result;

    CloseHandle(th->handle);
    free(th);
    return 0;
}

#endif                          /* WIN32 */