pg_dumpall.c

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/*-------------------------------------------------------------------------
 *
 * pg_dumpall.c
 *
 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * pg_dumpall forces all pg_dump output to be text, since it also outputs
 * text into the same output stream.
 *
 * src/bin/pg_dump/pg_dumpall.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres_fe.h"

#include <time.h>
#include <unistd.h>

#include "common/connect.h"
#include "common/file_utils.h"
#include "common/logging.h"
#include "common/string.h"
#include "dumputils.h"
#include "fe_utils/string_utils.h"
#include "getopt_long.h"
#include "pg_backup.h"

/* version string we expect back from pg_dump */
#define PGDUMP_VERSIONSTR "pg_dump (PostgreSQL) " PG_VERSION "\n"


static void help(void);

static void dropRoles(PGconn *conn);
static void dumpRoles(PGconn *conn);
static void dumpRoleMembership(PGconn *conn);
static void dumpGroups(PGconn *conn);
static void dropTablespaces(PGconn *conn);
static void dumpTablespaces(PGconn *conn);
static void dropDBs(PGconn *conn);
static void dumpUserConfig(PGconn *conn, const char *username);
static void dumpDatabases(PGconn *conn);
static void dumpTimestamp(const char *msg);
static int  runPgDump(const char *dbname, const char *create_opts);
static void buildShSecLabels(PGconn *conn,
                             const char *catalog_name, Oid objectId,
                             const char *objtype, const char *objname,
                             PQExpBuffer buffer);
static PGconn *connectDatabase(const char *dbname, const char *connstr, const char *pghost, const char *pgport,
                               const char *pguser, trivalue prompt_password, bool fail_on_error);
static char *constructConnStr(const char **keywords, const char **values);
static PGresult *executeQuery(PGconn *conn, const char *query);
static void executeCommand(PGconn *conn, const char *query);
static void expand_dbname_patterns(PGconn *conn, SimpleStringList *patterns,
                                   SimpleStringList *names);

static char pg_dump_bin[MAXPGPATH];
static const char *progname;
static PQExpBuffer pgdumpopts;
static char *connstr = "";
static bool output_clean = false;
static bool skip_acls = false;
static bool verbose = false;
static bool dosync = true;

static int  binary_upgrade = 0;
static int  column_inserts = 0;
static int  disable_dollar_quoting = 0;
static int  disable_triggers = 0;
static int  if_exists = 0;
static int  inserts = 0;
static int  no_tablespaces = 0;
static int  use_setsessauth = 0;
static int  no_comments = 0;
static int  no_publications = 0;
static int  no_security_labels = 0;
static int  no_subscriptions = 0;
static int  no_unlogged_table_data = 0;
static int  no_role_passwords = 0;
static int  server_version;
static int  load_via_partition_root = 0;
static int  on_conflict_do_nothing = 0;

static char role_catalog[10];
#define PG_AUTHID "pg_authid"
#define PG_ROLES  "pg_roles "

static FILE *OPF;
static char *filename = NULL;

static SimpleStringList database_exclude_patterns = {NULL, NULL};
static SimpleStringList database_exclude_names = {NULL, NULL};

#define exit_nicely(code) exit(code)

int
main(int argc, char *argv[])
{
    static struct option long_options[] = {
        {"data-only", no_argument, NULL, 'a'},
        {"clean", no_argument, NULL, 'c'},
        {"encoding", required_argument, NULL, 'E'},
        {"file", required_argument, NULL, 'f'},
        {"globals-only", no_argument, NULL, 'g'},
        {"host", required_argument, NULL, 'h'},
        {"dbname", required_argument, NULL, 'd'},
        {"database", required_argument, NULL, 'l'},
        {"no-owner", no_argument, NULL, 'O'},
        {"port", required_argument, NULL, 'p'},
        {"roles-only", no_argument, NULL, 'r'},
        {"schema-only", no_argument, NULL, 's'},
        {"superuser", required_argument, NULL, 'S'},
        {"tablespaces-only", no_argument, NULL, 't'},
        {"username", required_argument, NULL, 'U'},
        {"verbose", no_argument, NULL, 'v'},
        {"no-password", no_argument, NULL, 'w'},
        {"password", no_argument, NULL, 'W'},
        {"no-privileges", no_argument, NULL, 'x'},
        {"no-acl", no_argument, NULL, 'x'},

        /*
         * the following options don't have an equivalent short option letter
         */
        {"attribute-inserts", no_argument, &column_inserts, 1},
        {"binary-upgrade", no_argument, &binary_upgrade, 1},
        {"column-inserts", no_argument, &column_inserts, 1},
        {"disable-dollar-quoting", no_argument, &disable_dollar_quoting, 1},
        {"disable-triggers", no_argument, &disable_triggers, 1},
        {"exclude-database", required_argument, NULL, 6},
        {"extra-float-digits", required_argument, NULL, 5},
        {"if-exists", no_argument, &if_exists, 1},
        {"inserts", no_argument, &inserts, 1},
        {"lock-wait-timeout", required_argument, NULL, 2},
        {"no-tablespaces", no_argument, &no_tablespaces, 1},
        {"quote-all-identifiers", no_argument, &quote_all_identifiers, 1},
        {"load-via-partition-root", no_argument, &load_via_partition_root, 1},
        {"role", required_argument, NULL, 3},
        {"use-set-session-authorization", no_argument, &use_setsessauth, 1},
        {"no-comments", no_argument, &no_comments, 1},
        {"no-publications", no_argument, &no_publications, 1},
        {"no-role-passwords", no_argument, &no_role_passwords, 1},
        {"no-security-labels", no_argument, &no_security_labels, 1},
        {"no-subscriptions", no_argument, &no_subscriptions, 1},
        {"no-sync", no_argument, NULL, 4},
        {"no-unlogged-table-data", no_argument, &no_unlogged_table_data, 1},
        {"on-conflict-do-nothing", no_argument, &on_conflict_do_nothing, 1},
        {"rows-per-insert", required_argument, NULL, 7},

        {NULL, 0, NULL, 0}
    };

    char       *pghost = NULL;
    char       *pgport = NULL;
    char       *pguser = NULL;
    char       *pgdb = NULL;
    char       *use_role = NULL;
    const char *dumpencoding = NULL;
    trivalue    prompt_password = TRI_DEFAULT;
    bool        data_only = false;
    bool        globals_only = false;
    bool        roles_only = false;
    bool        tablespaces_only = false;
    PGconn     *conn;
    int         encoding;
    const char *std_strings;
    int         c,
                ret;
    int         optindex;

    pg_logging_init(argv[0]);
    pg_logging_set_level(PG_LOG_WARNING);
    set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_dump"));
    progname = get_progname(argv[0]);

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

    if ((ret = find_other_exec(argv[0], "pg_dump", PGDUMP_VERSIONSTR,
                               pg_dump_bin)) < 0)
    {
        char        full_path[MAXPGPATH];

        if (find_my_exec(argv[0], full_path) < 0)
            strlcpy(full_path, progname, sizeof(full_path));

        if (ret == -1)
            pg_log_error("The program \"%s\" is needed by %s but was not found in the\n"
                         "same directory as \"%s\".\n"
                         "Check your installation.",
                         "pg_dump", progname, full_path);
        else
            pg_log_error("The program \"%s\" was found by \"%s\"\n"
                         "but was not the same version as %s.\n"
                         "Check your installation.",
                         "pg_dump", full_path, progname);
        exit_nicely(1);
    }

    pgdumpopts = createPQExpBuffer();

    while ((c = getopt_long(argc, argv, "acd:E:f:gh:l:Op:rsS:tU:vwWx", long_options, &optindex)) != -1)
    {
        switch (c)
        {
            case 'a':
                data_only = true;
                appendPQExpBufferStr(pgdumpopts, " -a");
                break;

            case 'c':
                output_clean = true;
                break;

            case 'd':
                connstr = pg_strdup(optarg);
                break;

            case 'E':
                dumpencoding = pg_strdup(optarg);
                appendPQExpBufferStr(pgdumpopts, " -E ");
                appendShellString(pgdumpopts, optarg);
                break;

            case 'f':
                filename = pg_strdup(optarg);
                appendPQExpBufferStr(pgdumpopts, " -f ");
                appendShellString(pgdumpopts, filename);
                break;

            case 'g':
                globals_only = true;
                break;

            case 'h':
                pghost = pg_strdup(optarg);
                break;

            case 'l':
                pgdb = pg_strdup(optarg);
                break;

            case 'O':
                appendPQExpBufferStr(pgdumpopts, " -O");
                break;

            case 'p':
                pgport = pg_strdup(optarg);
                break;

            case 'r':
                roles_only = true;
                break;

            case 's':
                appendPQExpBufferStr(pgdumpopts, " -s");
                break;

            case 'S':
                appendPQExpBufferStr(pgdumpopts, " -S ");
                appendShellString(pgdumpopts, optarg);
                break;

            case 't':
                tablespaces_only = true;
                break;

            case 'U':
                pguser = pg_strdup(optarg);
                break;

            case 'v':
                verbose = true;
                pg_logging_increase_verbosity();
                appendPQExpBufferStr(pgdumpopts, " -v");
                break;

            case 'w':
                prompt_password = TRI_NO;
                appendPQExpBufferStr(pgdumpopts, " -w");
                break;

            case 'W':
                prompt_password = TRI_YES;
                appendPQExpBufferStr(pgdumpopts, " -W");
                break;

            case 'x':
                skip_acls = true;
                appendPQExpBufferStr(pgdumpopts, " -x");
                break;

            case 0:
                break;

            case 2:
                appendPQExpBufferStr(pgdumpopts, " --lock-wait-timeout ");
                appendShellString(pgdumpopts, optarg);
                break;

            case 3:
                use_role = pg_strdup(optarg);
                appendPQExpBufferStr(pgdumpopts, " --role ");
                appendShellString(pgdumpopts, use_role);
                break;

            case 4:
                dosync = false;
                appendPQExpBufferStr(pgdumpopts, " --no-sync");
                break;

            case 5:
                appendPQExpBufferStr(pgdumpopts, " --extra-float-digits ");
                appendShellString(pgdumpopts, optarg);
                break;

            case 6:
                simple_string_list_append(&database_exclude_patterns, optarg);
                break;

            case 7:
                appendPQExpBufferStr(pgdumpopts, " --rows-per-insert ");
                appendShellString(pgdumpopts, optarg);
                break;

            default:
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
                exit_nicely(1);
        }
    }

    /* Complain if any arguments remain */
    if (optind < argc)
    {
        pg_log_error("too many command-line arguments (first is \"%s\")",
                     argv[optind]);
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit_nicely(1);
    }

    if (database_exclude_patterns.head != NULL &&
        (globals_only || roles_only || tablespaces_only))
    {
        pg_log_error("option --exclude-database cannot be used together with -g/--globals-only, -r/--roles-only, or -t/--tablespaces-only");
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit_nicely(1);
    }

    /* Make sure the user hasn't specified a mix of globals-only options */
    if (globals_only && roles_only)
    {
        pg_log_error("options -g/--globals-only and -r/--roles-only cannot be used together");
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit_nicely(1);
    }

    if (globals_only && tablespaces_only)
    {
        pg_log_error("options -g/--globals-only and -t/--tablespaces-only cannot be used together");
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit_nicely(1);
    }

    if (if_exists && !output_clean)
    {
        pg_log_error("option --if-exists requires option -c/--clean");
        exit_nicely(1);
    }

    if (roles_only && tablespaces_only)
    {
        pg_log_error("options -r/--roles-only and -t/--tablespaces-only cannot be used together");
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit_nicely(1);
    }

    /*
     * If password values are not required in the dump, switch to using
     * pg_roles which is equally useful, just more likely to have unrestricted
     * access than pg_authid.
     */
    if (no_role_passwords)
        sprintf(role_catalog, "%s", PG_ROLES);
    else
        sprintf(role_catalog, "%s", PG_AUTHID);

    /* Add long options to the pg_dump argument list */
    if (binary_upgrade)
        appendPQExpBufferStr(pgdumpopts, " --binary-upgrade");
    if (column_inserts)
        appendPQExpBufferStr(pgdumpopts, " --column-inserts");
    if (disable_dollar_quoting)
        appendPQExpBufferStr(pgdumpopts, " --disable-dollar-quoting");
    if (disable_triggers)
        appendPQExpBufferStr(pgdumpopts, " --disable-triggers");
    if (inserts)
        appendPQExpBufferStr(pgdumpopts, " --inserts");
    if (no_tablespaces)
        appendPQExpBufferStr(pgdumpopts, " --no-tablespaces");
    if (quote_all_identifiers)
        appendPQExpBufferStr(pgdumpopts, " --quote-all-identifiers");
    if (load_via_partition_root)
        appendPQExpBufferStr(pgdumpopts, " --load-via-partition-root");
    if (use_setsessauth)
        appendPQExpBufferStr(pgdumpopts, " --use-set-session-authorization");
    if (no_comments)
        appendPQExpBufferStr(pgdumpopts, " --no-comments");
    if (no_publications)
        appendPQExpBufferStr(pgdumpopts, " --no-publications");
    if (no_security_labels)
        appendPQExpBufferStr(pgdumpopts, " --no-security-labels");
    if (no_subscriptions)
        appendPQExpBufferStr(pgdumpopts, " --no-subscriptions");
    if (no_unlogged_table_data)
        appendPQExpBufferStr(pgdumpopts, " --no-unlogged-table-data");
    if (on_conflict_do_nothing)
        appendPQExpBufferStr(pgdumpopts, " --on-conflict-do-nothing");

    /*
     * If there was a database specified on the command line, use that,
     * otherwise try to connect to database "postgres", and failing that
     * "template1".  "postgres" is the preferred choice for 8.1 and later
     * servers, but it usually will not exist on older ones.
     */
    if (pgdb)
    {
        conn = connectDatabase(pgdb, connstr, pghost, pgport, pguser,
                               prompt_password, false);

        if (!conn)
        {
            pg_log_error("could not connect to database \"%s\"", pgdb);
            exit_nicely(1);
        }
    }
    else
    {
        conn = connectDatabase("postgres", connstr, pghost, pgport, pguser,
                               prompt_password, false);
        if (!conn)
            conn = connectDatabase("template1", connstr, pghost, pgport, pguser,
                                   prompt_password, true);

        if (!conn)
        {
            pg_log_error("could not connect to databases \"postgres\" or \"template1\"\n"
                         "Please specify an alternative database.");
            fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                    progname);
            exit_nicely(1);
        }
    }

    /*
     * Get a list of database names that match the exclude patterns
     */
    expand_dbname_patterns(conn, &database_exclude_patterns,
                           &database_exclude_names);

    /*
     * Open the output file if required, otherwise use stdout
     */
    if (filename)
    {
        OPF = fopen(filename, PG_BINARY_W);
        if (!OPF)
        {
            pg_log_error("could not open output file \"%s\": %m",
                         filename);
            exit_nicely(1);
        }
    }
    else
        OPF = stdout;

    /*
     * Set the client encoding if requested.
     */
    if (dumpencoding)
    {
        if (PQsetClientEncoding(conn, dumpencoding) < 0)
        {
            pg_log_error("invalid client encoding \"%s\" specified",
                         dumpencoding);
            exit_nicely(1);
        }
    }

    /*
     * Get the active encoding and the standard_conforming_strings setting, so
     * we know how to escape strings.
     */
    encoding = PQclientEncoding(conn);
    std_strings = PQparameterStatus(conn, "standard_conforming_strings");
    if (!std_strings)
        std_strings = "off";

    /* Set the role if requested */
    if (use_role && server_version >= 80100)
    {
        PQExpBuffer query = createPQExpBuffer();

        appendPQExpBuffer(query, "SET ROLE %s", fmtId(use_role));
        executeCommand(conn, query->data);
        destroyPQExpBuffer(query);
    }

    /* Force quoting of all identifiers if requested. */
    if (quote_all_identifiers && server_version >= 90100)
        executeCommand(conn, "SET quote_all_identifiers = true");

    fprintf(OPF, "--\n-- PostgreSQL database cluster dump\n--\n\n");
    if (verbose)
        dumpTimestamp("Started on");

    /*
     * We used to emit \connect postgres here, but that served no purpose
     * other than to break things for installations without a postgres
     * database.  Everything we're restoring here is a global, so whichever
     * database we're connected to at the moment is fine.
     */

    /* Restore will need to write to the target cluster */
    fprintf(OPF, "SET default_transaction_read_only = off;\n\n");

    /* Replicate encoding and std_strings in output */
    fprintf(OPF, "SET client_encoding = '%s';\n",
            pg_encoding_to_char(encoding));
    fprintf(OPF, "SET standard_conforming_strings = %s;\n", std_strings);
    if (strcmp(std_strings, "off") == 0)
        fprintf(OPF, "SET escape_string_warning = off;\n");
    fprintf(OPF, "\n");

    if (!data_only)
    {
        /*
         * If asked to --clean, do that first.  We can avoid detailed
         * dependency analysis because databases never depend on each other,
         * and tablespaces never depend on each other.  Roles could have
         * grants to each other, but DROP ROLE will clean those up silently.
         */
        if (output_clean)
        {
            if (!globals_only && !roles_only && !tablespaces_only)
                dropDBs(conn);

            if (!roles_only && !no_tablespaces)
                dropTablespaces(conn);

            if (!tablespaces_only)
                dropRoles(conn);
        }

        /*
         * Now create objects as requested.  Be careful that option logic here
         * is the same as for drops above.
         */
        if (!tablespaces_only)
        {
            /* Dump roles (users) */
            dumpRoles(conn);

            /* Dump role memberships --- need different method for pre-8.1 */
            if (server_version >= 80100)
                dumpRoleMembership(conn);
            else
                dumpGroups(conn);
        }

        /* Dump tablespaces */
        if (!roles_only && !no_tablespaces)
            dumpTablespaces(conn);
    }

    if (!globals_only && !roles_only && !tablespaces_only)
        dumpDatabases(conn);

    PQfinish(conn);

    if (verbose)
        dumpTimestamp("Completed on");
    fprintf(OPF, "--\n-- PostgreSQL database cluster dump complete\n--\n\n");

    if (filename)
    {
        fclose(OPF);

        /* sync the resulting file, errors are not fatal */
        if (dosync)
            (void) fsync_fname(filename, false);
    }

    exit_nicely(0);
}


static void
help(void)
{
    printf(_("%s extracts a PostgreSQL database cluster into an SQL script file.\n\n"), progname);
    printf(_("Usage:\n"));
    printf(_("  %s [OPTION]...\n"), progname);

    printf(_("\nGeneral options:\n"));
    printf(_("  -f, --file=FILENAME          output file name\n"));
    printf(_("  -v, --verbose                verbose mode\n"));
    printf(_("  -V, --version                output version information, then exit\n"));
    printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
    printf(_("  -?, --help                   show this help, then exit\n"));
    printf(_("\nOptions controlling the output content:\n"));
    printf(_("  -a, --data-only              dump only the data, not the schema\n"));
    printf(_("  -c, --clean                  clean (drop) databases before recreating\n"));
    printf(_("  -E, --encoding=ENCODING      dump the data in encoding ENCODING\n"));
    printf(_("  -g, --globals-only           dump only global objects, no databases\n"));
    printf(_("  -O, --no-owner               skip restoration of object ownership\n"));
    printf(_("  -r, --roles-only             dump only roles, no databases or tablespaces\n"));
    printf(_("  -s, --schema-only            dump only the schema, no data\n"));
    printf(_("  -S, --superuser=NAME         superuser user name to use in the dump\n"));
    printf(_("  -t, --tablespaces-only       dump only tablespaces, no databases or roles\n"));
    printf(_("  -x, --no-privileges          do not dump privileges (grant/revoke)\n"));
    printf(_("  --binary-upgrade             for use by upgrade utilities only\n"));
    printf(_("  --column-inserts             dump data as INSERT commands with column names\n"));
    printf(_("  --disable-dollar-quoting     disable dollar quoting, use SQL standard quoting\n"));
    printf(_("  --disable-triggers           disable triggers during data-only restore\n"));
    printf(_("  --exclude-database=PATTERN   exclude databases whose name matches PATTERN\n"));
    printf(_("  --extra-float-digits=NUM     override default setting for extra_float_digits\n"));
    printf(_("  --if-exists                  use IF EXISTS when dropping objects\n"));
    printf(_("  --inserts                    dump data as INSERT commands, rather than COPY\n"));
    printf(_("  --load-via-partition-root    load partitions via the root table\n"));
    printf(_("  --no-comments                do not dump comments\n"));
    printf(_("  --no-publications            do not dump publications\n"));
    printf(_("  --no-role-passwords          do not dump passwords for roles\n"));
    printf(_("  --no-security-labels         do not dump security label assignments\n"));
    printf(_("  --no-subscriptions           do not dump subscriptions\n"));
    printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
    printf(_("  --no-tablespaces             do not dump tablespace assignments\n"));
    printf(_("  --no-unlogged-table-data     do not dump unlogged table data\n"));
    printf(_("  --on-conflict-do-nothing     add ON CONFLICT DO NOTHING to INSERT commands\n"));
    printf(_("  --quote-all-identifiers      quote all identifiers, even if not key words\n"));
    printf(_("  --rows-per-insert=NROWS      number of rows per INSERT; implies --inserts\n"));
    printf(_("  --use-set-session-authorization\n"
             "                               use SET SESSION AUTHORIZATION commands instead of\n"
             "                               ALTER OWNER commands to set ownership\n"));

    printf(_("\nConnection options:\n"));
    printf(_("  -d, --dbname=CONNSTR     connect using connection string\n"));
    printf(_("  -h, --host=HOSTNAME      database server host or socket directory\n"));
    printf(_("  -l, --database=DBNAME    alternative default database\n"));
    printf(_("  -p, --port=PORT          database server port number\n"));
    printf(_("  -U, --username=NAME      connect as specified database user\n"));
    printf(_("  -w, --no-password        never prompt for password\n"));
    printf(_("  -W, --password           force password prompt (should happen automatically)\n"));
    printf(_("  --role=ROLENAME          do SET ROLE before dump\n"));

    printf(_("\nIf -f/--file is not used, then the SQL script will be written to the standard\n"
             "output.\n\n"));
    printf(_("Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}


/*
 * Drop roles
 */
static void
dropRoles(PGconn *conn)
{
    PQExpBuffer buf = createPQExpBuffer();
    PGresult   *res;
    int         i_rolname;
    int         i;

    if (server_version >= 90600)
        printfPQExpBuffer(buf,
                          "SELECT rolname "
                          "FROM %s "
                          "WHERE rolname !~ '^pg_' "
                          "ORDER BY 1", role_catalog);
    else if (server_version >= 80100)
        printfPQExpBuffer(buf,
                          "SELECT rolname "
                          "FROM %s "
                          "ORDER BY 1", role_catalog);
    else
        printfPQExpBuffer(buf,
                          "SELECT usename as rolname "
                          "FROM pg_shadow "
                          "UNION "
                          "SELECT groname as rolname "
                          "FROM pg_group "
                          "ORDER BY 1");

    res = executeQuery(conn, buf->data);

    i_rolname = PQfnumber(res, "rolname");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Drop roles\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        const char *rolename;

        rolename = PQgetvalue(res, i, i_rolname);

        fprintf(OPF, "DROP ROLE %s%s;\n",
                if_exists ? "IF EXISTS " : "",
                fmtId(rolename));
    }

    PQclear(res);
    destroyPQExpBuffer(buf);

    fprintf(OPF, "\n\n");
}

/*
 * Dump roles
 */
static void
dumpRoles(PGconn *conn)
{
    PQExpBuffer buf = createPQExpBuffer();
    PGresult   *res;
    int         i_oid,
                i_rolname,
                i_rolsuper,
                i_rolinherit,
                i_rolcreaterole,
                i_rolcreatedb,
                i_rolcanlogin,
                i_rolconnlimit,
                i_rolpassword,
                i_rolvaliduntil,
                i_rolreplication,
                i_rolbypassrls,
                i_rolcomment,
                i_is_current_user;
    int         i;

    /* note: rolconfig is dumped later */
    if (server_version >= 90600)
        printfPQExpBuffer(buf,
                          "SELECT oid, rolname, rolsuper, rolinherit, "
                          "rolcreaterole, rolcreatedb, "
                          "rolcanlogin, rolconnlimit, rolpassword, "
                          "rolvaliduntil, rolreplication, rolbypassrls, "
                          "pg_catalog.shobj_description(oid, '%s') as rolcomment, "
                          "rolname = current_user AS is_current_user "
                          "FROM %s "
                          "WHERE rolname !~ '^pg_' "
                          "ORDER BY 2", role_catalog, role_catalog);
    else if (server_version >= 90500)
        printfPQExpBuffer(buf,
                          "SELECT oid, rolname, rolsuper, rolinherit, "
                          "rolcreaterole, rolcreatedb, "
                          "rolcanlogin, rolconnlimit, rolpassword, "
                          "rolvaliduntil, rolreplication, rolbypassrls, "
                          "pg_catalog.shobj_description(oid, '%s') as rolcomment, "
                          "rolname = current_user AS is_current_user "
                          "FROM %s "
                          "ORDER BY 2", role_catalog, role_catalog);
    else if (server_version >= 90100)
        printfPQExpBuffer(buf,
                          "SELECT oid, rolname, rolsuper, rolinherit, "
                          "rolcreaterole, rolcreatedb, "
                          "rolcanlogin, rolconnlimit, rolpassword, "
                          "rolvaliduntil, rolreplication, "
                          "false as rolbypassrls, "
                          "pg_catalog.shobj_description(oid, '%s') as rolcomment, "
                          "rolname = current_user AS is_current_user "
                          "FROM %s "
                          "ORDER BY 2", role_catalog, role_catalog);
    else if (server_version >= 80200)
        printfPQExpBuffer(buf,
                          "SELECT oid, rolname, rolsuper, rolinherit, "
                          "rolcreaterole, rolcreatedb, "
                          "rolcanlogin, rolconnlimit, rolpassword, "
                          "rolvaliduntil, false as rolreplication, "
                          "false as rolbypassrls, "
                          "pg_catalog.shobj_description(oid, '%s') as rolcomment, "
                          "rolname = current_user AS is_current_user "
                          "FROM %s "
                          "ORDER BY 2", role_catalog, role_catalog);
    else if (server_version >= 80100)
        printfPQExpBuffer(buf,
                          "SELECT oid, rolname, rolsuper, rolinherit, "
                          "rolcreaterole, rolcreatedb, "
                          "rolcanlogin, rolconnlimit, rolpassword, "
                          "rolvaliduntil, false as rolreplication, "
                          "false as rolbypassrls, "
                          "null as rolcomment, "
                          "rolname = current_user AS is_current_user "
                          "FROM %s "
                          "ORDER BY 2", role_catalog);
    else
        printfPQExpBuffer(buf,
                          "SELECT 0 as oid, usename as rolname, "
                          "usesuper as rolsuper, "
                          "true as rolinherit, "
                          "usesuper as rolcreaterole, "
                          "usecreatedb as rolcreatedb, "
                          "true as rolcanlogin, "
                          "-1 as rolconnlimit, "
                          "passwd as rolpassword, "
                          "valuntil as rolvaliduntil, "
                          "false as rolreplication, "
                          "false as rolbypassrls, "
                          "null as rolcomment, "
                          "usename = current_user AS is_current_user "
                          "FROM pg_shadow "
                          "UNION ALL "
                          "SELECT 0 as oid, groname as rolname, "
                          "false as rolsuper, "
                          "true as rolinherit, "
                          "false as rolcreaterole, "
                          "false as rolcreatedb, "
                          "false as rolcanlogin, "
                          "-1 as rolconnlimit, "
                          "null::text as rolpassword, "
                          "null::timestamptz as rolvaliduntil, "
                          "false as rolreplication, "
                          "false as rolbypassrls, "
                          "null as rolcomment, "
                          "false AS is_current_user "
                          "FROM pg_group "
                          "WHERE NOT EXISTS (SELECT 1 FROM pg_shadow "
                          " WHERE usename = groname) "
                          "ORDER BY 2");

    res = executeQuery(conn, buf->data);

    i_oid = PQfnumber(res, "oid");
    i_rolname = PQfnumber(res, "rolname");
    i_rolsuper = PQfnumber(res, "rolsuper");
    i_rolinherit = PQfnumber(res, "rolinherit");
    i_rolcreaterole = PQfnumber(res, "rolcreaterole");
    i_rolcreatedb = PQfnumber(res, "rolcreatedb");
    i_rolcanlogin = PQfnumber(res, "rolcanlogin");
    i_rolconnlimit = PQfnumber(res, "rolconnlimit");
    i_rolpassword = PQfnumber(res, "rolpassword");
    i_rolvaliduntil = PQfnumber(res, "rolvaliduntil");
    i_rolreplication = PQfnumber(res, "rolreplication");
    i_rolbypassrls = PQfnumber(res, "rolbypassrls");
    i_rolcomment = PQfnumber(res, "rolcomment");
    i_is_current_user = PQfnumber(res, "is_current_user");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Roles\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        const char *rolename;
        Oid         auth_oid;

        auth_oid = atooid(PQgetvalue(res, i, i_oid));
        rolename = PQgetvalue(res, i, i_rolname);

        if (strncmp(rolename, "pg_", 3) == 0)
        {
            pg_log_warning("role name starting with \"pg_\" skipped (%s)",
                           rolename);
            continue;
        }

        resetPQExpBuffer(buf);

        if (binary_upgrade)
        {
            appendPQExpBufferStr(buf, "\n-- For binary upgrade, must preserve pg_authid.oid\n");
            appendPQExpBuffer(buf,
                              "SELECT pg_catalog.binary_upgrade_set_next_pg_authid_oid('%u'::pg_catalog.oid);\n\n",
                              auth_oid);
        }

        /*
         * We dump CREATE ROLE followed by ALTER ROLE to ensure that the role
         * will acquire the right properties even if it already exists (ie, it
         * won't hurt for the CREATE to fail).  This is particularly important
         * for the role we are connected as, since even with --clean we will
         * have failed to drop it.  binary_upgrade cannot generate any errors,
         * so we assume the current role is already created.
         */
        if (!binary_upgrade ||
            strcmp(PQgetvalue(res, i, i_is_current_user), "f") == 0)
            appendPQExpBuffer(buf, "CREATE ROLE %s;\n", fmtId(rolename));
        appendPQExpBuffer(buf, "ALTER ROLE %s WITH", fmtId(rolename));

        if (strcmp(PQgetvalue(res, i, i_rolsuper), "t") == 0)
            appendPQExpBufferStr(buf, " SUPERUSER");
        else
            appendPQExpBufferStr(buf, " NOSUPERUSER");

        if (strcmp(PQgetvalue(res, i, i_rolinherit), "t") == 0)
            appendPQExpBufferStr(buf, " INHERIT");
        else
            appendPQExpBufferStr(buf, " NOINHERIT");

        if (strcmp(PQgetvalue(res, i, i_rolcreaterole), "t") == 0)
            appendPQExpBufferStr(buf, " CREATEROLE");
        else
            appendPQExpBufferStr(buf, " NOCREATEROLE");

        if (strcmp(PQgetvalue(res, i, i_rolcreatedb), "t") == 0)
            appendPQExpBufferStr(buf, " CREATEDB");
        else
            appendPQExpBufferStr(buf, " NOCREATEDB");

        if (strcmp(PQgetvalue(res, i, i_rolcanlogin), "t") == 0)
            appendPQExpBufferStr(buf, " LOGIN");
        else
            appendPQExpBufferStr(buf, " NOLOGIN");

        if (strcmp(PQgetvalue(res, i, i_rolreplication), "t") == 0)
            appendPQExpBufferStr(buf, " REPLICATION");
        else
            appendPQExpBufferStr(buf, " NOREPLICATION");

        if (strcmp(PQgetvalue(res, i, i_rolbypassrls), "t") == 0)
            appendPQExpBufferStr(buf, " BYPASSRLS");
        else
            appendPQExpBufferStr(buf, " NOBYPASSRLS");

        if (strcmp(PQgetvalue(res, i, i_rolconnlimit), "-1") != 0)
            appendPQExpBuffer(buf, " CONNECTION LIMIT %s",
                              PQgetvalue(res, i, i_rolconnlimit));


        if (!PQgetisnull(res, i, i_rolpassword) && !no_role_passwords)
        {
            appendPQExpBufferStr(buf, " PASSWORD ");
            appendStringLiteralConn(buf, PQgetvalue(res, i, i_rolpassword), conn);
        }

        if (!PQgetisnull(res, i, i_rolvaliduntil))
            appendPQExpBuffer(buf, " VALID UNTIL '%s'",
                              PQgetvalue(res, i, i_rolvaliduntil));

        appendPQExpBufferStr(buf, ";\n");

        if (!no_comments && !PQgetisnull(res, i, i_rolcomment))
        {
            appendPQExpBuffer(buf, "COMMENT ON ROLE %s IS ", fmtId(rolename));
            appendStringLiteralConn(buf, PQgetvalue(res, i, i_rolcomment), conn);
            appendPQExpBufferStr(buf, ";\n");
        }

        if (!no_security_labels && server_version >= 90200)
            buildShSecLabels(conn, "pg_authid", auth_oid,
                             "ROLE", rolename,
                             buf);

        fprintf(OPF, "%s", buf->data);
    }

    /*
     * Dump configuration settings for roles after all roles have been dumped.
     * We do it this way because config settings for roles could mention the
     * names of other roles.
     */
    for (i = 0; i < PQntuples(res); i++)
        dumpUserConfig(conn, PQgetvalue(res, i, i_rolname));

    PQclear(res);

    fprintf(OPF, "\n\n");

    destroyPQExpBuffer(buf);
}


/*
 * Dump role memberships.  This code is used for 8.1 and later servers.
 *
 * Note: we expect dumpRoles already created all the roles, but there is
 * no membership yet.
 */
static void
dumpRoleMembership(PGconn *conn)
{
    PQExpBuffer buf = createPQExpBuffer();
    PGresult   *res;
    int         i;

    printfPQExpBuffer(buf, "SELECT ur.rolname AS roleid, "
                      "um.rolname AS member, "
                      "a.admin_option, "
                      "ug.rolname AS grantor "
                      "FROM pg_auth_members a "
                      "LEFT JOIN %s ur on ur.oid = a.roleid "
                      "LEFT JOIN %s um on um.oid = a.member "
                      "LEFT JOIN %s ug on ug.oid = a.grantor "
                      "WHERE NOT (ur.rolname ~ '^pg_' AND um.rolname ~ '^pg_')"
                      "ORDER BY 1,2,3", role_catalog, role_catalog, role_catalog);
    res = executeQuery(conn, buf->data);

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Role memberships\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        char       *roleid = PQgetvalue(res, i, 0);
        char       *member = PQgetvalue(res, i, 1);
        char       *option = PQgetvalue(res, i, 2);

        fprintf(OPF, "GRANT %s", fmtId(roleid));
        fprintf(OPF, " TO %s", fmtId(member));
        if (*option == 't')
            fprintf(OPF, " WITH ADMIN OPTION");

        /*
         * We don't track the grantor very carefully in the backend, so cope
         * with the possibility that it has been dropped.
         */
        if (!PQgetisnull(res, i, 3))
        {
            char       *grantor = PQgetvalue(res, i, 3);

            fprintf(OPF, " GRANTED BY %s", fmtId(grantor));
        }
        fprintf(OPF, ";\n");
    }

    PQclear(res);
    destroyPQExpBuffer(buf);

    fprintf(OPF, "\n\n");
}

/*
 * Dump group memberships from a pre-8.1 server.  It's annoying that we
 * can't share any useful amount of code with the post-8.1 case, but
 * the catalog representations are too different.
 *
 * Note: we expect dumpRoles already created all the roles, but there is
 * no membership yet.
 */
static void
dumpGroups(PGconn *conn)
{
    PQExpBuffer buf = createPQExpBuffer();
    PGresult   *res;
    int         i;

    res = executeQuery(conn,
                       "SELECT groname, grolist FROM pg_group ORDER BY 1");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Role memberships\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        char       *groname = PQgetvalue(res, i, 0);
        char       *grolist = PQgetvalue(res, i, 1);
        PGresult   *res2;
        int         j;

        /*
         * Array representation is {1,2,3} ... convert to (1,2,3)
         */
        if (strlen(grolist) < 3)
            continue;

        grolist = pg_strdup(grolist);
        grolist[0] = '(';
        grolist[strlen(grolist) - 1] = ')';
        printfPQExpBuffer(buf,
                          "SELECT usename FROM pg_shadow "
                          "WHERE usesysid IN %s ORDER BY 1",
                          grolist);
        free(grolist);

        res2 = executeQuery(conn, buf->data);

        for (j = 0; j < PQntuples(res2); j++)
        {
            char       *usename = PQgetvalue(res2, j, 0);

            /*
             * Don't try to grant a role to itself; can happen if old
             * installation has identically named user and group.
             */
            if (strcmp(groname, usename) == 0)
                continue;

            fprintf(OPF, "GRANT %s", fmtId(groname));
            fprintf(OPF, " TO %s;\n", fmtId(usename));
        }

        PQclear(res2);
    }

    PQclear(res);
    destroyPQExpBuffer(buf);

    fprintf(OPF, "\n\n");
}


/*
 * Drop tablespaces.
 */
static void
dropTablespaces(PGconn *conn)
{
    PGresult   *res;
    int         i;

    /*
     * Get all tablespaces except built-in ones (which we assume are named
     * pg_xxx)
     */
    res = executeQuery(conn, "SELECT spcname "
                       "FROM pg_catalog.pg_tablespace "
                       "WHERE spcname !~ '^pg_' "
                       "ORDER BY 1");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Drop tablespaces\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        char       *spcname = PQgetvalue(res, i, 0);

        fprintf(OPF, "DROP TABLESPACE %s%s;\n",
                if_exists ? "IF EXISTS " : "",
                fmtId(spcname));
    }

    PQclear(res);

    fprintf(OPF, "\n\n");
}

/*
 * Dump tablespaces.
 */
static void
dumpTablespaces(PGconn *conn)
{
    PGresult   *res;
    int         i;

    /*
     * Get all tablespaces except built-in ones (which we assume are named
     * pg_xxx)
     *
     * For the tablespace ACLs, as of 9.6, we extract both the positive (as
     * spcacl) and negative (as rspcacl) ACLs, relative to the default ACL for
     * tablespaces, which are then passed to buildACLCommands() below.
     *
     * See buildACLQueries() and buildACLCommands().
     *
     * The order in which privileges are in the ACL string (the order they
     * have been GRANT'd in, which the backend maintains) must be preserved to
     * ensure that GRANTs WITH GRANT OPTION and subsequent GRANTs based on
     * those are dumped in the correct order.
     *
     * Note that we do not support initial privileges (pg_init_privs) on
     * tablespaces, so this logic cannot make use of buildACLQueries().
     */
    if (server_version >= 90600)
        res = executeQuery(conn, "SELECT oid, spcname, "
                           "pg_catalog.pg_get_userbyid(spcowner) AS spcowner, "
                           "pg_catalog.pg_tablespace_location(oid), "
                           "(SELECT array_agg(acl ORDER BY row_n) FROM "
                           "  (SELECT acl, row_n FROM "
                           "     unnest(coalesce(spcacl,acldefault('t',spcowner))) "
                           "     WITH ORDINALITY AS perm(acl,row_n) "
                           "   WHERE NOT EXISTS ( "
                           "     SELECT 1 "
                           "     FROM unnest(acldefault('t',spcowner)) "
                           "       AS init(init_acl) "
                           "     WHERE acl = init_acl)) AS spcacls) "
                           " AS spcacl, "
                           "(SELECT array_agg(acl ORDER BY row_n) FROM "
                           "  (SELECT acl, row_n FROM "
                           "     unnest(acldefault('t',spcowner)) "
                           "     WITH ORDINALITY AS initp(acl,row_n) "
                           "   WHERE NOT EXISTS ( "
                           "     SELECT 1 "
                           "     FROM unnest(coalesce(spcacl,acldefault('t',spcowner))) "
                           "       AS permp(orig_acl) "
                           "     WHERE acl = orig_acl)) AS rspcacls) "
                           " AS rspcacl, "
                           "array_to_string(spcoptions, ', '),"
                           "pg_catalog.shobj_description(oid, 'pg_tablespace') "
                           "FROM pg_catalog.pg_tablespace "
                           "WHERE spcname !~ '^pg_' "
                           "ORDER BY 1");
    else if (server_version >= 90200)
        res = executeQuery(conn, "SELECT oid, spcname, "
                           "pg_catalog.pg_get_userbyid(spcowner) AS spcowner, "
                           "pg_catalog.pg_tablespace_location(oid), "
                           "spcacl, '' as rspcacl, "
                           "array_to_string(spcoptions, ', '),"
                           "pg_catalog.shobj_description(oid, 'pg_tablespace') "
                           "FROM pg_catalog.pg_tablespace "
                           "WHERE spcname !~ '^pg_' "
                           "ORDER BY 1");
    else if (server_version >= 90000)
        res = executeQuery(conn, "SELECT oid, spcname, "
                           "pg_catalog.pg_get_userbyid(spcowner) AS spcowner, "
                           "spclocation, spcacl, '' as rspcacl, "
                           "array_to_string(spcoptions, ', '),"
                           "pg_catalog.shobj_description(oid, 'pg_tablespace') "
                           "FROM pg_catalog.pg_tablespace "
                           "WHERE spcname !~ '^pg_' "
                           "ORDER BY 1");
    else if (server_version >= 80200)
        res = executeQuery(conn, "SELECT oid, spcname, "
                           "pg_catalog.pg_get_userbyid(spcowner) AS spcowner, "
                           "spclocation, spcacl, '' as rspcacl, null, "
                           "pg_catalog.shobj_description(oid, 'pg_tablespace') "
                           "FROM pg_catalog.pg_tablespace "
                           "WHERE spcname !~ '^pg_' "
                           "ORDER BY 1");
    else
        res = executeQuery(conn, "SELECT oid, spcname, "
                           "pg_catalog.pg_get_userbyid(spcowner) AS spcowner, "
                           "spclocation, spcacl, '' as rspcacl, "
                           "null, null "
                           "FROM pg_catalog.pg_tablespace "
                           "WHERE spcname !~ '^pg_' "
                           "ORDER BY 1");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Tablespaces\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        PQExpBuffer buf = createPQExpBuffer();
        Oid         spcoid = atooid(PQgetvalue(res, i, 0));
        char       *spcname = PQgetvalue(res, i, 1);
        char       *spcowner = PQgetvalue(res, i, 2);
        char       *spclocation = PQgetvalue(res, i, 3);
        char       *spcacl = PQgetvalue(res, i, 4);
        char       *rspcacl = PQgetvalue(res, i, 5);
        char       *spcoptions = PQgetvalue(res, i, 6);
        char       *spccomment = PQgetvalue(res, i, 7);
        char       *fspcname;

        /* needed for buildACLCommands() */
        fspcname = pg_strdup(fmtId(spcname));

        appendPQExpBuffer(buf, "CREATE TABLESPACE %s", fspcname);
        appendPQExpBuffer(buf, " OWNER %s", fmtId(spcowner));

        appendPQExpBufferStr(buf, " LOCATION ");
        appendStringLiteralConn(buf, spclocation, conn);
        appendPQExpBufferStr(buf, ";\n");

        if (spcoptions && spcoptions[0] != '\0')
            appendPQExpBuffer(buf, "ALTER TABLESPACE %s SET (%s);\n",
                              fspcname, spcoptions);

        if (!skip_acls &&
            !buildACLCommands(fspcname, NULL, NULL, "TABLESPACE",
                              spcacl, rspcacl,
                              spcowner, "", server_version, buf))
        {
            pg_log_error("could not parse ACL list (%s) for tablespace \"%s\"",
                         spcacl, spcname);
            PQfinish(conn);
            exit_nicely(1);
        }

        if (!no_comments && spccomment && spccomment[0] != '\0')
        {
            appendPQExpBuffer(buf, "COMMENT ON TABLESPACE %s IS ", fspcname);
            appendStringLiteralConn(buf, spccomment, conn);
            appendPQExpBufferStr(buf, ";\n");
        }

        if (!no_security_labels && server_version >= 90200)
            buildShSecLabels(conn, "pg_tablespace", spcoid,
                             "TABLESPACE", spcname,
                             buf);

        fprintf(OPF, "%s", buf->data);

        free(fspcname);
        destroyPQExpBuffer(buf);
    }

    PQclear(res);
    fprintf(OPF, "\n\n");
}


/*
 * Dump commands to drop each database.
 */
static void
dropDBs(PGconn *conn)
{
    PGresult   *res;
    int         i;

    /*
     * Skip databases marked not datallowconn, since we'd be unable to connect
     * to them anyway.  This must agree with dumpDatabases().
     */
    res = executeQuery(conn,
                       "SELECT datname "
                       "FROM pg_database d "
                       "WHERE datallowconn "
                       "ORDER BY datname");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Drop databases (except postgres and template1)\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        char       *dbname = PQgetvalue(res, i, 0);

        /*
         * Skip "postgres" and "template1"; dumpDatabases() will deal with
         * them specially.  Also, be sure to skip "template0", even if for
         * some reason it's not marked !datallowconn.
         */
        if (strcmp(dbname, "template1") != 0 &&
            strcmp(dbname, "template0") != 0 &&
            strcmp(dbname, "postgres") != 0)
        {
            fprintf(OPF, "DROP DATABASE %s%s;\n",
                    if_exists ? "IF EXISTS " : "",
                    fmtId(dbname));
        }
    }

    PQclear(res);

    fprintf(OPF, "\n\n");
}


/*
 * Dump user-specific configuration
 */
static void
dumpUserConfig(PGconn *conn, const char *username)
{
    PQExpBuffer buf = createPQExpBuffer();
    int         count = 1;
    bool        first = true;

    for (;;)
    {
        PGresult   *res;

        if (server_version >= 90000)
            printfPQExpBuffer(buf, "SELECT setconfig[%d] FROM pg_db_role_setting WHERE "
                              "setdatabase = 0 AND setrole = "
                              "(SELECT oid FROM %s WHERE rolname = ", count, role_catalog);
        else if (server_version >= 80100)
            printfPQExpBuffer(buf, "SELECT rolconfig[%d] FROM %s WHERE rolname = ", count, role_catalog);
        else
            printfPQExpBuffer(buf, "SELECT useconfig[%d] FROM pg_shadow WHERE usename = ", count);
        appendStringLiteralConn(buf, username, conn);
        if (server_version >= 90000)
            appendPQExpBufferChar(buf, ')');

        res = executeQuery(conn, buf->data);
        if (PQntuples(res) == 1 &&
            !PQgetisnull(res, 0, 0))
        {
            /* comment at section start, only if needed */
            if (first)
            {
                fprintf(OPF, "--\n-- User Configurations\n--\n\n");
                first = false;
            }

            fprintf(OPF, "--\n-- User Config \"%s\"\n--\n\n", username);
            resetPQExpBuffer(buf);
            makeAlterConfigCommand(conn, PQgetvalue(res, 0, 0),
                                   "ROLE", username, NULL, NULL,
                                   buf);
            fprintf(OPF, "%s", buf->data);
            PQclear(res);
            count++;
        }
        else
        {
            PQclear(res);
            break;
        }
    }

    destroyPQExpBuffer(buf);
}

/*
 * Find a list of database names that match the given patterns.
 * See also expand_table_name_patterns() in pg_dump.c
 */
static void
expand_dbname_patterns(PGconn *conn,
                       SimpleStringList *patterns,
                       SimpleStringList *names)
{
    PQExpBuffer query;
    PGresult   *res;

    if (patterns->head == NULL)
        return;                 /* nothing to do */

    query = createPQExpBuffer();

    /*
     * The loop below runs multiple SELECTs, which might sometimes result in
     * duplicate entries in the name list, but we don't care, since all we're
     * going to do is test membership of the list.
     */

    for (SimpleStringListCell *cell = patterns->head; cell; cell = cell->next)
    {
        appendPQExpBufferStr(query,
                             "SELECT datname FROM pg_catalog.pg_database n\n");
        processSQLNamePattern(conn, query, cell->val, false,
                              false, NULL, "datname", NULL, NULL);

        res = executeQuery(conn, query->data);
        for (int i = 0; i < PQntuples(res); i++)
        {
            simple_string_list_append(names, PQgetvalue(res, i, 0));
        }

        PQclear(res);
        resetPQExpBuffer(query);
    }

    destroyPQExpBuffer(query);
}

/*
 * Dump contents of databases.
 */
static void
dumpDatabases(PGconn *conn)
{
    PGresult   *res;
    int         i;

    /*
     * Skip databases marked not datallowconn, since we'd be unable to connect
     * to them anyway.  This must agree with dropDBs().
     *
     * We arrange for template1 to be processed first, then we process other
     * DBs in alphabetical order.  If we just did them all alphabetically, we
     * might find ourselves trying to drop the "postgres" database while still
     * connected to it.  This makes trying to run the restore script while
     * connected to "template1" a bad idea, but there's no fixed order that
     * doesn't have some failure mode with --clean.
     */
    res = executeQuery(conn,
                       "SELECT datname "
                       "FROM pg_database d "
                       "WHERE datallowconn "
                       "ORDER BY (datname <> 'template1'), datname");

    if (PQntuples(res) > 0)
        fprintf(OPF, "--\n-- Databases\n--\n\n");

    for (i = 0; i < PQntuples(res); i++)
    {
        char       *dbname = PQgetvalue(res, i, 0);
        const char *create_opts;
        int         ret;

        /* Skip template0, even if it's not marked !datallowconn. */
        if (strcmp(dbname, "template0") == 0)
            continue;

        /* Skip any explicitly excluded database */
        if (simple_string_list_member(&database_exclude_names, dbname))
        {
            pg_log_info("excluding database \"%s\"", dbname);
            continue;
        }

        pg_log_info("dumping database \"%s\"", dbname);

        fprintf(OPF, "--\n-- Database \"%s\" dump\n--\n\n", dbname);

        /*
         * We assume that "template1" and "postgres" already exist in the
         * target installation.  dropDBs() won't have removed them, for fear
         * of removing the DB the restore script is initially connected to. If
         * --clean was specified, tell pg_dump to drop and recreate them;
         * otherwise we'll merely restore their contents.  Other databases
         * should simply be created.
         */
        if (strcmp(dbname, "template1") == 0 || strcmp(dbname, "postgres") == 0)
        {
            if (output_clean)
                create_opts = "--clean --create";
            else
            {
                create_opts = "";
                /* Since pg_dump won't emit a \connect command, we must */
                fprintf(OPF, "\\connect %s\n\n", dbname);
            }
        }
        else
            create_opts = "--create";

        if (filename)
            fclose(OPF);

        ret = runPgDump(dbname, create_opts);
        if (ret != 0)
        {
            pg_log_error("pg_dump failed on database \"%s\", exiting", dbname);
            exit_nicely(1);
        }

        if (filename)
        {
            OPF = fopen(filename, PG_BINARY_A);
            if (!OPF)
            {
                pg_log_error("could not re-open the output file \"%s\": %m",
                             filename);
                exit_nicely(1);
            }
        }

    }

    PQclear(res);
}



/*
 * Run pg_dump on dbname, with specified options.
 */
static int
runPgDump(const char *dbname, const char *create_opts)
{
    PQExpBuffer connstrbuf = createPQExpBuffer();
    PQExpBuffer cmd = createPQExpBuffer();
    int         ret;

    appendPQExpBuffer(cmd, "\"%s\" %s %s", pg_dump_bin,
                      pgdumpopts->data, create_opts);

    /*
     * If we have a filename, use the undocumented plain-append pg_dump
     * format.
     */
    if (filename)
        appendPQExpBufferStr(cmd, " -Fa ");
    else
        appendPQExpBufferStr(cmd, " -Fp ");

    /*
     * Append the database name to the already-constructed stem of connection
     * string.
     */
    appendPQExpBuffer(connstrbuf, "%s dbname=", connstr);
    appendConnStrVal(connstrbuf, dbname);

    appendShellString(cmd, connstrbuf->data);

    pg_log_info("running \"%s\"", cmd->data);

    fflush(stdout);
    fflush(stderr);

    ret = system(cmd->data);

    destroyPQExpBuffer(cmd);
    destroyPQExpBuffer(connstrbuf);

    return ret;
}

/*
 * buildShSecLabels
 *
 * Build SECURITY LABEL command(s) for a shared object
 *
 * The caller has to provide object type and identity in two separate formats:
 * catalog_name (e.g., "pg_database") and object OID, as well as
 * type name (e.g., "DATABASE") and object name (not pre-quoted).
 *
 * The command(s) are appended to "buffer".
 */
static void
buildShSecLabels(PGconn *conn, const char *catalog_name, Oid objectId,
                 const char *objtype, const char *objname,
                 PQExpBuffer buffer)
{
    PQExpBuffer sql = createPQExpBuffer();
    PGresult   *res;

    buildShSecLabelQuery(catalog_name, objectId, sql);
    res = executeQuery(conn, sql->data);
    emitShSecLabels(conn, res, buffer, objtype, objname);

    PQclear(res);
    destroyPQExpBuffer(sql);
}

/*
 * Make a database connection with the given parameters.  An
 * interactive password prompt is automatically issued if required.
 *
 * If fail_on_error is false, we return NULL without printing any message
 * on failure, but preserve any prompted password for the next try.
 *
 * On success, the global variable 'connstr' is set to a connection string
 * containing the options used.
 */
static PGconn *
connectDatabase(const char *dbname, const char *connection_string,
                const char *pghost, const char *pgport, const char *pguser,
                trivalue prompt_password, bool fail_on_error)
{
    PGconn     *conn;
    bool        new_pass;
    const char *remoteversion_str;
    int         my_version;
    const char **keywords = NULL;
    const char **values = NULL;
    PQconninfoOption *conn_opts = NULL;
    static char *password = NULL;

    if (prompt_password == TRI_YES && !password)
        password = simple_prompt("Password: ", false);

    /*
     * Start the connection.  Loop until we have a password if requested by
     * backend.
     */
    do
    {
        int         argcount = 6;
        PQconninfoOption *conn_opt;
        char       *err_msg = NULL;
        int         i = 0;

        if (keywords)
            free(keywords);
        if (values)
            free(values);
        if (conn_opts)
            PQconninfoFree(conn_opts);

        /*
         * Merge the connection info inputs given in form of connection string
         * and other options.  Explicitly discard any dbname value in the
         * connection string; otherwise, PQconnectdbParams() would interpret
         * that value as being itself a connection string.
         */
        if (connection_string)
        {
            conn_opts = PQconninfoParse(connection_string, &err_msg);
            if (conn_opts == NULL)
            {
                pg_log_error("%s", err_msg);
                exit_nicely(1);
            }

            for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
            {
                if (conn_opt->val != NULL && conn_opt->val[0] != '\0' &&
                    strcmp(conn_opt->keyword, "dbname") != 0)
                    argcount++;
            }

            keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
            values = pg_malloc0((argcount + 1) * sizeof(*values));

            for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
            {
                if (conn_opt->val != NULL && conn_opt->val[0] != '\0' &&
                    strcmp(conn_opt->keyword, "dbname") != 0)
                {
                    keywords[i] = conn_opt->keyword;
                    values[i] = conn_opt->val;
                    i++;
                }
            }
        }
        else
        {
            keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
            values = pg_malloc0((argcount + 1) * sizeof(*values));
        }

        if (pghost)
        {
            keywords[i] = "host";
            values[i] = pghost;
            i++;
        }
        if (pgport)
        {
            keywords[i] = "port";
            values[i] = pgport;
            i++;
        }
        if (pguser)
        {
            keywords[i] = "user";
            values[i] = pguser;
            i++;
        }
        if (password)
        {
            keywords[i] = "password";
            values[i] = password;
            i++;
        }
        if (dbname)
        {
            keywords[i] = "dbname";
            values[i] = dbname;
            i++;
        }
        keywords[i] = "fallback_application_name";
        values[i] = progname;
        i++;

        new_pass = false;
        conn = PQconnectdbParams(keywords, values, true);

        if (!conn)
        {
            pg_log_error("could not connect to database \"%s\"", dbname);
            exit_nicely(1);
        }

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

    /* check to see that the backend connection was successfully made */
    if (PQstatus(conn) == CONNECTION_BAD)
    {
        if (fail_on_error)
        {
            pg_log_error("%s", PQerrorMessage(conn));
            exit_nicely(1);
        }
        else
        {
            PQfinish(conn);

            free(keywords);
            free(values);
            PQconninfoFree(conn_opts);

            return NULL;
        }
    }

    /*
     * Ok, connected successfully. Remember the options used, in the form of a
     * connection string.
     */
    connstr = constructConnStr(keywords, values);

    free(keywords);
    free(values);
    PQconninfoFree(conn_opts);

    /* Check version */
    remoteversion_str = PQparameterStatus(conn, "server_version");
    if (!remoteversion_str)
    {
        pg_log_error("could not get server version");
        exit_nicely(1);
    }
    server_version = PQserverVersion(conn);
    if (server_version == 0)
    {
        pg_log_error("could not parse server version \"%s\"",
                     remoteversion_str);
        exit_nicely(1);
    }

    my_version = PG_VERSION_NUM;

    /*
     * We allow the server to be back to 8.0, and up to any minor release of
     * our own major version.  (See also version check in pg_dump.c.)
     */
    if (my_version != server_version
        && (server_version < 80000 ||
            (server_version / 100) > (my_version / 100)))
    {
        pg_log_error("server version: %s; %s version: %s",
                     remoteversion_str, progname, PG_VERSION);
        pg_log_error("aborting because of server version mismatch");
        exit_nicely(1);
    }

    PQclear(executeQuery(conn, ALWAYS_SECURE_SEARCH_PATH_SQL));

    return conn;
}

/* ----------
 * Construct a connection string from the given keyword/value pairs. It is
 * used to pass the connection options to the pg_dump subprocess.
 *
 * The following parameters are excluded:
 *  dbname      - varies in each pg_dump invocation
 *  password    - it's not secure to pass a password on the command line
 *  fallback_application_name - we'll let pg_dump set it
 * ----------
 */
static char *
constructConnStr(const char **keywords, const char **values)
{
    PQExpBuffer buf = createPQExpBuffer();
    char       *connstr;
    int         i;
    bool        firstkeyword = true;

    /* Construct a new connection string in key='value' format. */
    for (i = 0; keywords[i] != NULL; i++)
    {
        if (strcmp(keywords[i], "dbname") == 0 ||
            strcmp(keywords[i], "password") == 0 ||
            strcmp(keywords[i], "fallback_application_name") == 0)
            continue;

        if (!firstkeyword)
            appendPQExpBufferChar(buf, ' ');
        firstkeyword = false;
        appendPQExpBuffer(buf, "%s=", keywords[i]);
        appendConnStrVal(buf, values[i]);
    }

    connstr = pg_strdup(buf->data);
    destroyPQExpBuffer(buf);
    return connstr;
}

/*
 * Run a query, return the results, exit program on failure.
 */
static PGresult *
executeQuery(PGconn *conn, const char *query)
{
    PGresult   *res;

    pg_log_info("executing %s", query);

    res = PQexec(conn, query);
    if (!res ||
        PQresultStatus(res) != PGRES_TUPLES_OK)
    {
        pg_log_error("query failed: %s", PQerrorMessage(conn));
        pg_log_error("query was: %s", query);
        PQfinish(conn);
        exit_nicely(1);
    }

    return res;
}

/*
 * As above for a SQL command (which returns nothing).
 */
static void
executeCommand(PGconn *conn, const char *query)
{
    PGresult   *res;

    pg_log_info("executing %s", query);

    res = PQexec(conn, query);
    if (!res ||
        PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        pg_log_error("query failed: %s", PQerrorMessage(conn));
        pg_log_error("query was: %s", query);
        PQfinish(conn);
        exit_nicely(1);
    }

    PQclear(res);
}


/*
 * dumpTimestamp
 */
static void
dumpTimestamp(const char *msg)
{
    char        buf[64];
    time_t      now = time(NULL);

    if (strftime(buf, sizeof(buf), PGDUMP_STRFTIME_FMT, localtime(&now)) != 0)
        fprintf(OPF, "-- %s %s\n\n", msg, buf);
}