pg_upgrade.c

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/*
 *  pg_upgrade.c
 *
 *  main source file
 *
 *  Copyright (c) 2010-2024, PostgreSQL Global Development Group
 *  src/bin/pg_upgrade/pg_upgrade.c
 */
 
/*
 *  To simplify the upgrade process, we force certain system values to be
 *  identical between old and new clusters:
 *
 *  We control all assignments of pg_class.oid (and relfilenode) so toast
 *  oids are the same between old and new clusters.  This is important
 *  because toast oids are stored as toast pointers in user tables.
 *
 *  While pg_class.oid and pg_class.relfilenode are initially the same in a
 *  cluster, they can diverge due to CLUSTER, REINDEX, or VACUUM FULL. We
 *  control assignments of pg_class.relfilenode because we want the filenames
 *  to match between the old and new cluster.
 *
 *  We control assignment of pg_tablespace.oid because we want the oid to match
 *  between the old and new cluster.
 *
 *  We control all assignments of pg_type.oid because these oids are stored
 *  in user composite type values.
 *
 *  We control all assignments of pg_enum.oid because these oids are stored
 *  in user tables as enum values.
 *
 *  We control all assignments of pg_authid.oid for historical reasons (the
 *  oids used to be stored in pg_largeobject_metadata, which is now copied via
 *  SQL commands), that might change at some point in the future.
 */
 
 
 
#include "postgres_fe.h"
 
#include <time.h>
 
#ifdef HAVE_LANGINFO_H
#include <langinfo.h>
#endif
 
#include "catalog/pg_class_d.h"
#include "common/file_perm.h"
#include "common/logging.h"
#include "common/restricted_token.h"
#include "fe_utils/string_utils.h"
#include "pg_upgrade.h"
 
/*
 * Maximum number of pg_restore actions (TOC entries) to process within one
 * transaction.  At some point we might want to make this user-controllable,
 * but for now a hard-wired setting will suffice.
 */
#define RESTORE_TRANSACTION_SIZE 1000
 
static void set_locale_and_encoding(void);
static void prepare_new_cluster(void);
static void prepare_new_globals(void);
static void create_new_objects(void);
static void copy_xact_xlog_xid(void);
static void set_frozenxids(bool minmxid_only);
static void make_outputdirs(char *pgdata);
static void setup(char *argv0);
static void create_logical_replication_slots(void);
 
ClusterInfo old_cluster,
            new_cluster;
OSInfo      os_info;
 
char       *output_files[] = {
    SERVER_LOG_FILE,
#ifdef WIN32
    /* unique file for pg_ctl start */
    SERVER_START_LOG_FILE,
#endif
    UTILITY_LOG_FILE,
    INTERNAL_LOG_FILE,
    NULL
};
 
 
int
main(int argc, char **argv)
{
    char       *deletion_script_file_name = NULL;
 
    /*
     * pg_upgrade doesn't currently use common/logging.c, but initialize it
     * anyway because we might call common code that does.
     */
    pg_logging_init(argv[0]);
    set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_upgrade"));
 
    /* Set default restrictive mask until new cluster permissions are read */
    umask(PG_MODE_MASK_OWNER);
 
    parseCommandLine(argc, argv);
 
    get_restricted_token();
 
    adjust_data_dir(&old_cluster);
    adjust_data_dir(&new_cluster);
 
    /*
     * Set mask based on PGDATA permissions, needed for the creation of the
     * output directories with correct permissions.
     */
    if (!GetDataDirectoryCreatePerm(new_cluster.pgdata))
        pg_fatal("could not read permissions of directory \"%s\": %m",
                 new_cluster.pgdata);
 
    umask(pg_mode_mask);
 
    /*
     * This needs to happen after adjusting the data directory of the new
     * cluster in adjust_data_dir().
     */
    make_outputdirs(new_cluster.pgdata);
 
    setup(argv[0]);
 
    output_check_banner();
 
    check_cluster_versions();
 
    get_sock_dir(&old_cluster);
    get_sock_dir(&new_cluster);
 
    check_cluster_compatibility();
 
    check_and_dump_old_cluster();
 
 
    /* -- NEW -- */
    start_postmaster(&new_cluster, true);
 
    check_new_cluster();
    report_clusters_compatible();
 
    pg_log(PG_REPORT,
           "\n"
           "Performing Upgrade\n"
           "------------------");
 
    set_locale_and_encoding();
 
    prepare_new_cluster();
 
    stop_postmaster(false);
 
    /*
     * Destructive Changes to New Cluster
     */
 
    copy_xact_xlog_xid();
 
    /* New now using xids of the old system */
 
    /* -- NEW -- */
    start_postmaster(&new_cluster, true);
 
    prepare_new_globals();
 
    create_new_objects();
 
    stop_postmaster(false);
 
    /*
     * Most failures happen in create_new_objects(), which has completed at
     * this point.  We do this here because it is just before linking, which
     * will link the old and new cluster data files, preventing the old
     * cluster from being safely started once the new cluster is started.
     */
    if (user_opts.transfer_mode == TRANSFER_MODE_LINK)
        disable_old_cluster();
 
    transfer_all_new_tablespaces(&old_cluster.dbarr, &new_cluster.dbarr,
                                 old_cluster.pgdata, new_cluster.pgdata);
 
    /*
     * Assuming OIDs are only used in system tables, there is no need to
     * restore the OID counter because we have not transferred any OIDs from
     * the old system, but we do it anyway just in case.  We do it late here
     * because there is no need to have the schema load use new oids.
     */
    prep_status("Setting next OID for new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/pg_resetwal\" -o %u \"%s\"",
              new_cluster.bindir, old_cluster.controldata.chkpnt_nxtoid,
              new_cluster.pgdata);
    check_ok();
 
    /*
     * Migrate the logical slots to the new cluster.  Note that we need to do
     * this after resetting WAL because otherwise the required WAL would be
     * removed and slots would become unusable.  There is a possibility that
     * background processes might generate some WAL before we could create the
     * slots in the new cluster but we can ignore that WAL as that won't be
     * required downstream.
     */
    if (count_old_cluster_logical_slots())
    {
        start_postmaster(&new_cluster, true);
        create_logical_replication_slots();
        stop_postmaster(false);
    }
 
    if (user_opts.do_sync)
    {
        prep_status("Sync data directory to disk");
        exec_prog(UTILITY_LOG_FILE, NULL, true, true,
                  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
                  new_cluster.bindir,
                  new_cluster.pgdata,
                  user_opts.sync_method);
        check_ok();
    }
 
    create_script_for_old_cluster_deletion(&deletion_script_file_name);
 
    issue_warnings_and_set_wal_level();
 
    pg_log(PG_REPORT,
           "\n"
           "Upgrade Complete\n"
           "----------------");
 
    output_completion_banner(deletion_script_file_name);
 
    pg_free(deletion_script_file_name);
 
    cleanup_output_dirs();
 
    return 0;
}
 
/*
 * Create and assign proper permissions to the set of output directories
 * used to store any data generated internally, filling in log_opts in
 * the process.
 */
static void
make_outputdirs(char *pgdata)
{
    FILE       *fp;
    char      **filename;
    time_t      run_time = time(NULL);
    char        filename_path[MAXPGPATH];
    char        timebuf[128];
    struct timeval time;
    time_t      tt;
    int         len;
 
    log_opts.rootdir = (char *) pg_malloc0(MAXPGPATH);
    len = snprintf(log_opts.rootdir, MAXPGPATH, "%s/%s", pgdata, BASE_OUTPUTDIR);
    if (len >= MAXPGPATH)
        pg_fatal("directory path for new cluster is too long");
 
    /* BASE_OUTPUTDIR/$timestamp/ */
    gettimeofday(&time, NULL);
    tt = (time_t) time.tv_sec;
    strftime(timebuf, sizeof(timebuf), "%Y%m%dT%H%M%S", localtime(&tt));
    /* append milliseconds */
    snprintf(timebuf + strlen(timebuf), sizeof(timebuf) - strlen(timebuf),
             ".%03d", (int) (time.tv_usec / 1000));
    log_opts.basedir = (char *) pg_malloc0(MAXPGPATH);
    len = snprintf(log_opts.basedir, MAXPGPATH, "%s/%s", log_opts.rootdir,
                   timebuf);
    if (len >= MAXPGPATH)
        pg_fatal("directory path for new cluster is too long");
 
    /* BASE_OUTPUTDIR/$timestamp/dump/ */
    log_opts.dumpdir = (char *) pg_malloc0(MAXPGPATH);
    len = snprintf(log_opts.dumpdir, MAXPGPATH, "%s/%s/%s", log_opts.rootdir,
                   timebuf, DUMP_OUTPUTDIR);
    if (len >= MAXPGPATH)
        pg_fatal("directory path for new cluster is too long");
 
    /* BASE_OUTPUTDIR/$timestamp/log/ */
    log_opts.logdir = (char *) pg_malloc0(MAXPGPATH);
    len = snprintf(log_opts.logdir, MAXPGPATH, "%s/%s/%s", log_opts.rootdir,
                   timebuf, LOG_OUTPUTDIR);
    if (len >= MAXPGPATH)
        pg_fatal("directory path for new cluster is too long");
 
    /*
     * Ignore the error case where the root path exists, as it is kept the
     * same across runs.
     */
    if (mkdir(log_opts.rootdir, pg_dir_create_mode) < 0 && errno != EEXIST)
        pg_fatal("could not create directory \"%s\": %m", log_opts.rootdir);
    if (mkdir(log_opts.basedir, pg_dir_create_mode) < 0)
        pg_fatal("could not create directory \"%s\": %m", log_opts.basedir);
    if (mkdir(log_opts.dumpdir, pg_dir_create_mode) < 0)
        pg_fatal("could not create directory \"%s\": %m", log_opts.dumpdir);
    if (mkdir(log_opts.logdir, pg_dir_create_mode) < 0)
        pg_fatal("could not create directory \"%s\": %m", log_opts.logdir);
 
    len = snprintf(filename_path, sizeof(filename_path), "%s/%s",
                   log_opts.logdir, INTERNAL_LOG_FILE);
    if (len >= sizeof(filename_path))
        pg_fatal("directory path for new cluster is too long");
 
    if ((log_opts.internal = fopen_priv(filename_path, "a")) == NULL)
        pg_fatal("could not open log file \"%s\": %m", filename_path);
 
    /* label start of upgrade in logfiles */
    for (filename = output_files; *filename != NULL; filename++)
    {
        len = snprintf(filename_path, sizeof(filename_path), "%s/%s",
                       log_opts.logdir, *filename);
        if (len >= sizeof(filename_path))
            pg_fatal("directory path for new cluster is too long");
        if ((fp = fopen_priv(filename_path, "a")) == NULL)
            pg_fatal("could not write to log file \"%s\": %m", filename_path);
 
        fprintf(fp,
                "-----------------------------------------------------------------\n"
                "  pg_upgrade run on %s"
                "-----------------------------------------------------------------\n\n",
                ctime(&run_time));
        fclose(fp);
    }
}
 
 
static void
setup(char *argv0)
{
    /*
     * make sure the user has a clean environment, otherwise, we may confuse
     * libpq when we connect to one (or both) of the servers.
     */
    check_pghost_envvar();
 
    /*
     * In case the user hasn't specified the directory for the new binaries
     * with -B, default to using the path of the currently executed pg_upgrade
     * binary.
     */
    if (!new_cluster.bindir)
    {
        char        exec_path[MAXPGPATH];
 
        if (find_my_exec(argv0, exec_path) < 0)
            pg_fatal("%s: could not find own program executable", argv0);
        /* Trim off program name and keep just path */
        *last_dir_separator(exec_path) = '\0';
        canonicalize_path(exec_path);
        new_cluster.bindir = pg_strdup(exec_path);
    }
 
    verify_directories();
 
    /* no postmasters should be running, except for a live check */
    if (pid_lock_file_exists(old_cluster.pgdata))
    {
        /*
         * If we have a postmaster.pid file, try to start the server.  If it
         * starts, the pid file was stale, so stop the server.  If it doesn't
         * start, assume the server is running.  If the pid file is left over
         * from a server crash, this also allows any committed transactions
         * stored in the WAL to be replayed so they are not lost, because WAL
         * files are not transferred from old to new servers.  We later check
         * for a clean shutdown.
         */
        if (start_postmaster(&old_cluster, false))
            stop_postmaster(false);
        else
        {
            if (!user_opts.check)
                pg_fatal("There seems to be a postmaster servicing the old cluster.\n"
                         "Please shutdown that postmaster and try again.");
            else
                user_opts.live_check = true;
        }
    }
 
    /* same goes for the new postmaster */
    if (pid_lock_file_exists(new_cluster.pgdata))
    {
        if (start_postmaster(&new_cluster, false))
            stop_postmaster(false);
        else
            pg_fatal("There seems to be a postmaster servicing the new cluster.\n"
                     "Please shutdown that postmaster and try again.");
    }
}
 
 
/*
 * Copy locale and encoding information into the new cluster's template0.
 *
 * We need to copy the encoding, datlocprovider, datcollate, datctype, and
 * datlocale. We don't need datcollversion because that's never set for
 * template0.
 */
static void
set_locale_and_encoding(void)
{
    PGconn     *conn_new_template1;
    char       *datcollate_literal;
    char       *datctype_literal;
    char       *datlocale_literal = NULL;
    DbLocaleInfo *locale = old_cluster.template0;
 
    prep_status("Setting locale and encoding for new cluster");
 
    /* escape literals with respect to new cluster */
    conn_new_template1 = connectToServer(&new_cluster, "template1");
 
    datcollate_literal = PQescapeLiteral(conn_new_template1,
                                         locale->db_collate,
                                         strlen(locale->db_collate));
    datctype_literal = PQescapeLiteral(conn_new_template1,
                                       locale->db_ctype,
                                       strlen(locale->db_ctype));
    if (locale->db_locale)
        datlocale_literal = PQescapeLiteral(conn_new_template1,
                                            locale->db_locale,
                                            strlen(locale->db_locale));
    else
        datlocale_literal = pg_strdup("NULL");
 
    /* update template0 in new cluster */
    if (GET_MAJOR_VERSION(new_cluster.major_version) >= 1700)
        PQclear(executeQueryOrDie(conn_new_template1,
                                  "UPDATE pg_catalog.pg_database "
                                  "  SET encoding = %d, "
                                  "      datlocprovider = '%c', "
                                  "      datcollate = %s, "
                                  "      datctype = %s, "
                                  "      datlocale = %s "
                                  "  WHERE datname = 'template0' ",
                                  locale->db_encoding,
                                  locale->db_collprovider,
                                  datcollate_literal,
                                  datctype_literal,
                                  datlocale_literal));
    else if (GET_MAJOR_VERSION(new_cluster.major_version) >= 1500)
        PQclear(executeQueryOrDie(conn_new_template1,
                                  "UPDATE pg_catalog.pg_database "
                                  "  SET encoding = %d, "
                                  "      datlocprovider = '%c', "
                                  "      datcollate = %s, "
                                  "      datctype = %s, "
                                  "      daticulocale = %s "
                                  "  WHERE datname = 'template0' ",
                                  locale->db_encoding,
                                  locale->db_collprovider,
                                  datcollate_literal,
                                  datctype_literal,
                                  datlocale_literal));
    else
        PQclear(executeQueryOrDie(conn_new_template1,
                                  "UPDATE pg_catalog.pg_database "
                                  "  SET encoding = %d, "
                                  "      datcollate = %s, "
                                  "      datctype = %s "
                                  "  WHERE datname = 'template0' ",
                                  locale->db_encoding,
                                  datcollate_literal,
                                  datctype_literal));
 
    PQfreemem(datcollate_literal);
    PQfreemem(datctype_literal);
    PQfreemem(datlocale_literal);
 
    PQfinish(conn_new_template1);
 
    check_ok();
}
 
 
static void
prepare_new_cluster(void)
{
    /*
     * It would make more sense to freeze after loading the schema, but that
     * would cause us to lose the frozenxids restored by the load. We use
     * --analyze so autovacuum doesn't update statistics later
     */
    prep_status("Analyzing all rows in the new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/vacuumdb\" %s --all --analyze %s",
              new_cluster.bindir, cluster_conn_opts(&new_cluster),
              log_opts.verbose ? "--verbose" : "");
    check_ok();
 
    /*
     * We do freeze after analyze so pg_statistic is also frozen. template0 is
     * not frozen here, but data rows were frozen by initdb, and we set its
     * datfrozenxid, relfrozenxids, and relminmxid later to match the new xid
     * counter later.
     */
    prep_status("Freezing all rows in the new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/vacuumdb\" %s --all --freeze %s",
              new_cluster.bindir, cluster_conn_opts(&new_cluster),
              log_opts.verbose ? "--verbose" : "");
    check_ok();
}
 
 
static void
prepare_new_globals(void)
{
    /*
     * Before we restore anything, set frozenxids of initdb-created tables.
     */
    set_frozenxids(false);
 
    /*
     * Now restore global objects (roles and tablespaces).
     */
    prep_status("Restoring global objects in the new cluster");
 
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/psql\" " EXEC_PSQL_ARGS " %s -f \"%s/%s\"",
              new_cluster.bindir, cluster_conn_opts(&new_cluster),
              log_opts.dumpdir,
              GLOBALS_DUMP_FILE);
    check_ok();
}
 
 
static void
create_new_objects(void)
{
    int         dbnum;
    PGconn     *conn_new_template1;
 
    prep_status_progress("Restoring database schemas in the new cluster");
 
    /*
     * Ensure that any changes to template0 are fully written out to disk
     * prior to restoring the databases.  This is necessary because we use the
     * FILE_COPY strategy to create the databases (which testing has shown to
     * be faster), and when the server is in binary upgrade mode, it skips the
     * checkpoints this strategy ordinarily performs.
     */
    conn_new_template1 = connectToServer(&new_cluster, "template1");
    PQclear(executeQueryOrDie(conn_new_template1, "CHECKPOINT"));
    PQfinish(conn_new_template1);
 
    /*
     * We cannot process the template1 database concurrently with others,
     * because when it's transiently dropped, connection attempts would fail.
     * So handle it in a separate non-parallelized pass.
     */
    for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
    {
        char        sql_file_name[MAXPGPATH],
                    log_file_name[MAXPGPATH];
        DbInfo     *old_db = &old_cluster.dbarr.dbs[dbnum];
        const char *create_opts;
 
        /* Process only template1 in this pass */
        if (strcmp(old_db->db_name, "template1") != 0)
            continue;
 
        pg_log(PG_STATUS, "%s", old_db->db_name);
        snprintf(sql_file_name, sizeof(sql_file_name), DB_DUMP_FILE_MASK, old_db->db_oid);
        snprintf(log_file_name, sizeof(log_file_name), DB_DUMP_LOG_FILE_MASK, old_db->db_oid);
 
        /*
         * template1 database will already exist in the target installation,
         * so tell pg_restore to drop and recreate it; otherwise we would fail
         * to propagate its database-level properties.
         */
        create_opts = "--clean --create";
 
        exec_prog(log_file_name,
                  NULL,
                  true,
                  true,
                  "\"%s/pg_restore\" %s %s --exit-on-error --verbose "
                  "--transaction-size=%d "
                  "--dbname postgres \"%s/%s\"",
                  new_cluster.bindir,
                  cluster_conn_opts(&new_cluster),
                  create_opts,
                  RESTORE_TRANSACTION_SIZE,
                  log_opts.dumpdir,
                  sql_file_name);
 
        break;                  /* done once we've processed template1 */
    }
 
    for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
    {
        char        sql_file_name[MAXPGPATH],
                    log_file_name[MAXPGPATH];
        DbInfo     *old_db = &old_cluster.dbarr.dbs[dbnum];
        const char *create_opts;
        int         txn_size;
 
        /* Skip template1 in this pass */
        if (strcmp(old_db->db_name, "template1") == 0)
            continue;
 
        pg_log(PG_STATUS, "%s", old_db->db_name);
        snprintf(sql_file_name, sizeof(sql_file_name), DB_DUMP_FILE_MASK, old_db->db_oid);
        snprintf(log_file_name, sizeof(log_file_name), DB_DUMP_LOG_FILE_MASK, old_db->db_oid);
 
        /*
         * postgres database will already exist in the target installation, so
         * tell pg_restore to drop and recreate it; otherwise we would fail to
         * propagate its database-level properties.
         */
        if (strcmp(old_db->db_name, "postgres") == 0)
            create_opts = "--clean --create";
        else
            create_opts = "--create";
 
        /*
         * In parallel mode, reduce the --transaction-size of each restore job
         * so that the total number of locks that could be held across all the
         * jobs stays in bounds.
         */
        txn_size = RESTORE_TRANSACTION_SIZE;
        if (user_opts.jobs > 1)
        {
            txn_size /= user_opts.jobs;
            /* Keep some sanity if -j is huge */
            txn_size = Max(txn_size, 10);
        }
 
        parallel_exec_prog(log_file_name,
                           NULL,
                           "\"%s/pg_restore\" %s %s --exit-on-error --verbose "
                           "--transaction-size=%d "
                           "--dbname template1 \"%s/%s\"",
                           new_cluster.bindir,
                           cluster_conn_opts(&new_cluster),
                           create_opts,
                           txn_size,
                           log_opts.dumpdir,
                           sql_file_name);
    }
 
    /* reap all children */
    while (reap_child(true) == true)
        ;
 
    end_progress_output();
    check_ok();
 
    /*
     * We don't have minmxids for databases or relations in pre-9.3 clusters,
     * so set those after we have restored the schema.
     */
    if (GET_MAJOR_VERSION(old_cluster.major_version) <= 902)
        set_frozenxids(true);
 
    /* update new_cluster info now that we have objects in the databases */
    get_db_rel_and_slot_infos(&new_cluster);
}
 
/*
 * Delete the given subdirectory contents from the new cluster
 */
static void
remove_new_subdir(const char *subdir, bool rmtopdir)
{
    char        new_path[MAXPGPATH];
 
    prep_status("Deleting files from new %s", subdir);
 
    snprintf(new_path, sizeof(new_path), "%s/%s", new_cluster.pgdata, subdir);
    if (!rmtree(new_path, rmtopdir))
        pg_fatal("could not delete directory \"%s\"", new_path);
 
    check_ok();
}
 
/*
 * Copy the files from the old cluster into it
 */
static void
copy_subdir_files(const char *old_subdir, const char *new_subdir)
{
    char        old_path[MAXPGPATH];
    char        new_path[MAXPGPATH];
 
    remove_new_subdir(new_subdir, true);
 
    snprintf(old_path, sizeof(old_path), "%s/%s", old_cluster.pgdata, old_subdir);
    snprintf(new_path, sizeof(new_path), "%s/%s", new_cluster.pgdata, new_subdir);
 
    prep_status("Copying old %s to new server", old_subdir);
 
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
#ifndef WIN32
              "cp -Rf \"%s\" \"%s\"",
#else
    /* flags: everything, no confirm, quiet, overwrite read-only */
              "xcopy /e /y /q /r \"%s\" \"%s\\\"",
#endif
              old_path, new_path);
 
    check_ok();
}
 
static void
copy_xact_xlog_xid(void)
{
    /*
     * Copy old commit logs to new data dir. pg_clog has been renamed to
     * pg_xact in post-10 clusters.
     */
    copy_subdir_files(GET_MAJOR_VERSION(old_cluster.major_version) <= 906 ?
                      "pg_clog" : "pg_xact",
                      GET_MAJOR_VERSION(new_cluster.major_version) <= 906 ?
                      "pg_clog" : "pg_xact");
 
    prep_status("Setting oldest XID for new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/pg_resetwal\" -f -u %u \"%s\"",
              new_cluster.bindir, old_cluster.controldata.chkpnt_oldstxid,
              new_cluster.pgdata);
    check_ok();
 
    /* set the next transaction id and epoch of the new cluster */
    prep_status("Setting next transaction ID and epoch for new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/pg_resetwal\" -f -x %u \"%s\"",
              new_cluster.bindir, old_cluster.controldata.chkpnt_nxtxid,
              new_cluster.pgdata);
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/pg_resetwal\" -f -e %u \"%s\"",
              new_cluster.bindir, old_cluster.controldata.chkpnt_nxtepoch,
              new_cluster.pgdata);
    /* must reset commit timestamp limits also */
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
              "\"%s/pg_resetwal\" -f -c %u,%u \"%s\"",
              new_cluster.bindir,
              old_cluster.controldata.chkpnt_nxtxid,
              old_cluster.controldata.chkpnt_nxtxid,
              new_cluster.pgdata);
    check_ok();
 
    /*
     * If the old server is before the MULTIXACT_FORMATCHANGE_CAT_VER change
     * (see pg_upgrade.h) and the new server is after, then we don't copy
     * pg_multixact files, but we need to reset pg_control so that the new
     * server doesn't attempt to read multis older than the cutoff value.
     */
    if (old_cluster.controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER &&
        new_cluster.controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER)
    {
        copy_subdir_files("pg_multixact/offsets", "pg_multixact/offsets");
        copy_subdir_files("pg_multixact/members", "pg_multixact/members");
 
        prep_status("Setting next multixact ID and offset for new cluster");
 
        /*
         * we preserve all files and contents, so we must preserve both "next"
         * counters here and the oldest multi present on system.
         */
        exec_prog(UTILITY_LOG_FILE, NULL, true, true,
                  "\"%s/pg_resetwal\" -O %u -m %u,%u \"%s\"",
                  new_cluster.bindir,
                  old_cluster.controldata.chkpnt_nxtmxoff,
                  old_cluster.controldata.chkpnt_nxtmulti,
                  old_cluster.controldata.chkpnt_oldstMulti,
                  new_cluster.pgdata);
        check_ok();
    }
    else if (new_cluster.controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER)
    {
        /*
         * Remove offsets/0000 file created by initdb that no longer matches
         * the new multi-xid value.  "members" starts at zero so no need to
         * remove it.
         */
        remove_new_subdir("pg_multixact/offsets", false);
 
        prep_status("Setting oldest multixact ID in new cluster");
 
        /*
         * We don't preserve files in this case, but it's important that the
         * oldest multi is set to the latest value used by the old system, so
         * that multixact.c returns the empty set for multis that might be
         * present on disk.  We set next multi to the value following that; it
         * might end up wrapped around (i.e. 0) if the old cluster had
         * next=MaxMultiXactId, but multixact.c can cope with that just fine.
         */
        exec_prog(UTILITY_LOG_FILE, NULL, true, true,
                  "\"%s/pg_resetwal\" -m %u,%u \"%s\"",
                  new_cluster.bindir,
                  old_cluster.controldata.chkpnt_nxtmulti + 1,
                  old_cluster.controldata.chkpnt_nxtmulti,
                  new_cluster.pgdata);
        check_ok();
    }
 
    /* now reset the wal archives in the new cluster */
    prep_status("Resetting WAL archives");
    exec_prog(UTILITY_LOG_FILE, NULL, true, true,
    /* use timeline 1 to match controldata and no WAL history file */
              "\"%s/pg_resetwal\" -l 00000001%s \"%s\"", new_cluster.bindir,
              old_cluster.controldata.nextxlogfile + 8,
              new_cluster.pgdata);
    check_ok();
}
 
 
/*
 *  set_frozenxids()
 *
 * This is called on the new cluster before we restore anything, with
 * minmxid_only = false.  Its purpose is to ensure that all initdb-created
 * vacuumable tables have relfrozenxid/relminmxid matching the old cluster's
 * xid/mxid counters.  We also initialize the datfrozenxid/datminmxid of the
 * built-in databases to match.
 *
 * As we create user tables later, their relfrozenxid/relminmxid fields will
 * be restored properly by the binary-upgrade restore script.  Likewise for
 * user-database datfrozenxid/datminmxid.  However, if we're upgrading from a
 * pre-9.3 database, which does not store per-table or per-DB minmxid, then
 * the relminmxid/datminmxid values filled in by the restore script will just
 * be zeroes.
 *
 * Hence, with a pre-9.3 source database, a second call occurs after
 * everything is restored, with minmxid_only = true.  This pass will
 * initialize all tables and databases, both those made by initdb and user
 * objects, with the desired minmxid value.  frozenxid values are left alone.
 */
static void
set_frozenxids(bool minmxid_only)
{
    int         dbnum;
    PGconn     *conn,
               *conn_template1;
    PGresult   *dbres;
    int         ntups;
    int         i_datname;
    int         i_datallowconn;
 
    if (!minmxid_only)
        prep_status("Setting frozenxid and minmxid counters in new cluster");
    else
        prep_status("Setting minmxid counter in new cluster");
 
    conn_template1 = connectToServer(&new_cluster, "template1");
 
    if (!minmxid_only)
        /* set pg_database.datfrozenxid */
        PQclear(executeQueryOrDie(conn_template1,
                                  "UPDATE pg_catalog.pg_database "
                                  "SET  datfrozenxid = '%u'",
                                  old_cluster.controldata.chkpnt_nxtxid));
 
    /* set pg_database.datminmxid */
    PQclear(executeQueryOrDie(conn_template1,
                              "UPDATE pg_catalog.pg_database "
                              "SET  datminmxid = '%u'",
                              old_cluster.controldata.chkpnt_nxtmulti));
 
    /* get database names */
    dbres = executeQueryOrDie(conn_template1,
                              "SELECT   datname, datallowconn "
                              "FROM pg_catalog.pg_database");
 
    i_datname = PQfnumber(dbres, "datname");
    i_datallowconn = PQfnumber(dbres, "datallowconn");
 
    ntups = PQntuples(dbres);
    for (dbnum = 0; dbnum < ntups; dbnum++)
    {
        char       *datname = PQgetvalue(dbres, dbnum, i_datname);
        char       *datallowconn = PQgetvalue(dbres, dbnum, i_datallowconn);
 
        /*
         * We must update databases where datallowconn = false, e.g.
         * template0, because autovacuum increments their datfrozenxids,
         * relfrozenxids, and relminmxid even if autovacuum is turned off, and
         * even though all the data rows are already frozen.  To enable this,
         * we temporarily change datallowconn.
         */
        if (strcmp(datallowconn, "f") == 0)
            PQclear(executeQueryOrDie(conn_template1,
                                      "ALTER DATABASE %s ALLOW_CONNECTIONS = true",
                                      quote_identifier(datname)));
 
        conn = connectToServer(&new_cluster, datname);
 
        if (!minmxid_only)
            /* set pg_class.relfrozenxid */
            PQclear(executeQueryOrDie(conn,
                                      "UPDATE   pg_catalog.pg_class "
                                      "SET  relfrozenxid = '%u' "
            /* only heap, materialized view, and TOAST are vacuumed */
                                      "WHERE    relkind IN ("
                                      CppAsString2(RELKIND_RELATION) ", "
                                      CppAsString2(RELKIND_MATVIEW) ", "
                                      CppAsString2(RELKIND_TOASTVALUE) ")",
                                      old_cluster.controldata.chkpnt_nxtxid));
 
        /* set pg_class.relminmxid */
        PQclear(executeQueryOrDie(conn,
                                  "UPDATE   pg_catalog.pg_class "
                                  "SET  relminmxid = '%u' "
        /* only heap, materialized view, and TOAST are vacuumed */
                                  "WHERE    relkind IN ("
                                  CppAsString2(RELKIND_RELATION) ", "
                                  CppAsString2(RELKIND_MATVIEW) ", "
                                  CppAsString2(RELKIND_TOASTVALUE) ")",
                                  old_cluster.controldata.chkpnt_nxtmulti));
        PQfinish(conn);
 
        /* Reset datallowconn flag */
        if (strcmp(datallowconn, "f") == 0)
            PQclear(executeQueryOrDie(conn_template1,
                                      "ALTER DATABASE %s ALLOW_CONNECTIONS = false",
                                      quote_identifier(datname)));
    }
 
    PQclear(dbres);
 
    PQfinish(conn_template1);
 
    check_ok();
}
 
/*
 * create_logical_replication_slots()
 *
 * Similar to create_new_objects() but only restores logical replication slots.
 */
static void
create_logical_replication_slots(void)
{
    prep_status_progress("Restoring logical replication slots in the new cluster");
 
    for (int dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
    {
        DbInfo     *old_db = &old_cluster.dbarr.dbs[dbnum];
        LogicalSlotInfoArr *slot_arr = &old_db->slot_arr;
        PGconn     *conn;
        PQExpBuffer query;
 
        /* Skip this database if there are no slots */
        if (slot_arr->nslots == 0)
            continue;
 
        conn = connectToServer(&new_cluster, old_db->db_name);
        query = createPQExpBuffer();
 
        pg_log(PG_STATUS, "%s", old_db->db_name);
 
        for (int slotnum = 0; slotnum < slot_arr->nslots; slotnum++)
        {
            LogicalSlotInfo *slot_info = &slot_arr->slots[slotnum];
 
            /* Constructs a query for creating logical replication slots */
            appendPQExpBuffer(query,
                              "SELECT * FROM "
                              "pg_catalog.pg_create_logical_replication_slot(");
            appendStringLiteralConn(query, slot_info->slotname, conn);
            appendPQExpBuffer(query, ", ");
            appendStringLiteralConn(query, slot_info->plugin, conn);
 
            appendPQExpBuffer(query, ", false, %s, %s);",
                              slot_info->two_phase ? "true" : "false",
                              slot_info->failover ? "true" : "false");
 
            PQclear(executeQueryOrDie(conn, "%s", query->data));
 
            resetPQExpBuffer(query);
        }
 
        PQfinish(conn);
 
        destroyPQExpBuffer(query);
    }
 
    end_progress_output();
    check_ok();
 
    return;
}