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[PATCH v22 1/2] Split vacuumdb to create vacuuming.c/h 108+ messages / 4 participants [nested] [flat]
* [PATCH v22 1/2] Split vacuumdb to create vacuuming.c/h @ 2025-09-25 12:58 Álvaro Herrera <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: Álvaro Herrera @ 2025-09-25 12:58 UTC (permalink / raw) This allows these routines to be reused by a future utility heavily based on vacuumdb. Discussion: https://postgr.es/m/[email protected] --- src/bin/scripts/Makefile | 4 +- src/bin/scripts/meson.build | 28 +- src/bin/scripts/vacuumdb.c | 1055 +---------------------------------- src/bin/scripts/vacuuming.c | 1012 +++++++++++++++++++++++++++++++++ src/bin/scripts/vacuuming.h | 68 +++ 5 files changed, 1131 insertions(+), 1036 deletions(-) create mode 100644 src/bin/scripts/vacuuming.c create mode 100644 src/bin/scripts/vacuuming.h diff --git a/src/bin/scripts/Makefile b/src/bin/scripts/Makefile index f6b4d40810b..019ca06455d 100644 --- a/src/bin/scripts/Makefile +++ b/src/bin/scripts/Makefile @@ -28,7 +28,7 @@ createuser: createuser.o common.o $(WIN32RES) | submake-libpq submake-libpgport dropdb: dropdb.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils dropuser: dropuser.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils clusterdb: clusterdb.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils -vacuumdb: vacuumdb.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils +vacuumdb: vacuumdb.o vacuuming.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils reindexdb: reindexdb.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils pg_isready: pg_isready.o common.o $(WIN32RES) | submake-libpq submake-libpgport submake-libpgfeutils @@ -50,7 +50,7 @@ uninstall: clean distclean: rm -f $(addsuffix $(X), $(PROGRAMS)) $(addsuffix .o, $(PROGRAMS)) - rm -f common.o $(WIN32RES) + rm -f common.o vacuuming.o $(WIN32RES) rm -rf tmp_check export with_icu diff --git a/src/bin/scripts/meson.build b/src/bin/scripts/meson.build index 80df7c33257..a4fed59d1c9 100644 --- a/src/bin/scripts/meson.build +++ b/src/bin/scripts/meson.build @@ -12,7 +12,6 @@ binaries = [ 'createuser', 'dropuser', 'clusterdb', - 'vacuumdb', 'reindexdb', 'pg_isready', ] @@ -35,6 +34,33 @@ foreach binary : binaries bin_targets += binary endforeach +vacuuming_common = static_library('libvacuuming_common', + files('common.c', 'vacuuming.c'), + dependencies: [frontend_code, libpq], + kwargs: internal_lib_args, +) + +binaries = [ + 'vacuumdb', +] +foreach binary : binaries + binary_sources = files('@[email protected]'.format(binary)) + + if host_system == 'windows' + binary_sources += rc_bin_gen.process(win32ver_rc, extra_args: [ + '--NAME', binary, + '--FILEDESC', '@0@ - PostgreSQL utility'.format(binary),]) + endif + + binary = executable(binary, + binary_sources, + link_with: [vacuuming_common], + dependencies: [frontend_code, libpq], + kwargs: default_bin_args, + ) + bin_targets += binary +endforeach + tests += { 'name': 'scripts', 'sd': meson.current_source_dir(), diff --git a/src/bin/scripts/vacuumdb.c b/src/bin/scripts/vacuumdb.c index 6e30f223efe..00babc5c9c0 100644 --- a/src/bin/scripts/vacuumdb.c +++ b/src/bin/scripts/vacuumdb.c @@ -14,91 +14,13 @@ #include <limits.h> -#include "catalog/pg_attribute_d.h" -#include "catalog/pg_class_d.h" #include "common.h" -#include "common/connect.h" #include "common/logging.h" -#include "fe_utils/cancel.h" #include "fe_utils/option_utils.h" -#include "fe_utils/parallel_slot.h" -#include "fe_utils/query_utils.h" -#include "fe_utils/simple_list.h" -#include "fe_utils/string_utils.h" - - -/* vacuum options controlled by user flags */ -typedef struct vacuumingOptions -{ - bool analyze_only; - bool verbose; - bool and_analyze; - bool full; - bool freeze; - bool disable_page_skipping; - bool skip_locked; - int min_xid_age; - int min_mxid_age; - int parallel_workers; /* >= 0 indicates user specified the - * parallel degree, otherwise -1 */ - bool no_index_cleanup; - bool force_index_cleanup; - bool do_truncate; - bool process_main; - bool process_toast; - bool skip_database_stats; - char *buffer_usage_limit; - bool missing_stats_only; -} vacuumingOptions; - -/* object filter options */ -typedef enum -{ - OBJFILTER_NONE = 0, /* no filter used */ - OBJFILTER_ALL_DBS = (1 << 0), /* -a | --all */ - OBJFILTER_DATABASE = (1 << 1), /* -d | --dbname */ - OBJFILTER_TABLE = (1 << 2), /* -t | --table */ - OBJFILTER_SCHEMA = (1 << 3), /* -n | --schema */ - OBJFILTER_SCHEMA_EXCLUDE = (1 << 4), /* -N | --exclude-schema */ -} VacObjFilter; - -static VacObjFilter objfilter = OBJFILTER_NONE; - -static SimpleStringList *retrieve_objects(PGconn *conn, - vacuumingOptions *vacopts, - SimpleStringList *objects, - bool echo); - -static void vacuum_one_database(ConnParams *cparams, - vacuumingOptions *vacopts, - int stage, - SimpleStringList *objects, - SimpleStringList **found_objs, - int concurrentCons, - const char *progname, bool echo, bool quiet); - -static void vacuum_all_databases(ConnParams *cparams, - vacuumingOptions *vacopts, - bool analyze_in_stages, - SimpleStringList *objects, - int concurrentCons, - const char *progname, bool echo, bool quiet); - -static void prepare_vacuum_command(PQExpBuffer sql, int serverVersion, - vacuumingOptions *vacopts, const char *table); - -static void run_vacuum_command(PGconn *conn, const char *sql, bool echo, - const char *table); +#include "vacuuming.h" static void help(const char *progname); - -void check_objfilter(void); - -static char *escape_quotes(const char *src); - -/* For analyze-in-stages mode */ -#define ANALYZE_NO_STAGE -1 -#define ANALYZE_NUM_STAGES 3 +static void check_objfilter(VacObjFilter objfilter); int @@ -145,18 +67,16 @@ main(int argc, char *argv[]) int c; const char *dbname = NULL; const char *maintenance_db = NULL; - char *host = NULL; - char *port = NULL; - char *username = NULL; - enum trivalue prompt_password = TRI_DEFAULT; ConnParams cparams; bool echo = false; bool quiet = false; vacuumingOptions vacopts; bool analyze_in_stages = false; SimpleStringList objects = {NULL, NULL}; + VacObjFilter objfilter = OBJFILTER_NONE; int concurrentCons = 1; int tbl_count = 0; + int ret; /* initialize options */ memset(&vacopts, 0, sizeof(vacopts)); @@ -168,13 +88,18 @@ main(int argc, char *argv[]) vacopts.process_main = true; vacopts.process_toast = true; + /* the same for connection parameters */ + memset(&cparams, 0, sizeof(cparams)); + cparams.prompt_password = TRI_DEFAULT; + pg_logging_init(argv[0]); progname = get_progname(argv[0]); set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pgscripts")); handle_help_version_opts(argc, argv, "vacuumdb", help); - while ((c = getopt_long(argc, argv, "ad:efFh:j:n:N:p:P:qt:U:vwWzZ", long_options, &optindex)) != -1) + while ((c = getopt_long(argc, argv, "ad:efFh:j:n:N:p:P:qt:U:vwWzZ", + long_options, &optindex)) != -1) { switch (c) { @@ -195,7 +120,7 @@ main(int argc, char *argv[]) vacopts.freeze = true; break; case 'h': - host = pg_strdup(optarg); + cparams.pghost = pg_strdup(optarg); break; case 'j': if (!option_parse_int(optarg, "-j/--jobs", 1, INT_MAX, @@ -211,7 +136,7 @@ main(int argc, char *argv[]) simple_string_list_append(&objects, optarg); break; case 'p': - port = pg_strdup(optarg); + cparams.pgport = pg_strdup(optarg); break; case 'P': if (!option_parse_int(optarg, "-P/--parallel", 0, INT_MAX, @@ -227,16 +152,16 @@ main(int argc, char *argv[]) tbl_count++; break; case 'U': - username = pg_strdup(optarg); + cparams.pguser = pg_strdup(optarg); break; case 'v': vacopts.verbose = true; break; case 'w': - prompt_password = TRI_NO; + cparams.prompt_password = TRI_NO; break; case 'W': - prompt_password = TRI_YES; + cparams.prompt_password = TRI_YES; break; case 'z': vacopts.and_analyze = true; @@ -317,7 +242,7 @@ main(int argc, char *argv[]) * Validate the combination of filters specified in the command-line * options. */ - check_objfilter(); + check_objfilter(objfilter); if (vacopts.analyze_only) { @@ -380,74 +305,18 @@ main(int argc, char *argv[]) pg_fatal("cannot use the \"%s\" option without \"%s\" or \"%s\"", "missing-stats-only", "analyze-only", "analyze-in-stages"); - /* fill cparams except for dbname, which is set below */ - cparams.pghost = host; - cparams.pgport = port; - cparams.pguser = username; - cparams.prompt_password = prompt_password; - cparams.override_dbname = NULL; - - setup_cancel_handler(NULL); - - /* Avoid opening extra connections. */ - if (tbl_count && (concurrentCons > tbl_count)) - concurrentCons = tbl_count; - - if (objfilter & OBJFILTER_ALL_DBS) - { - cparams.dbname = maintenance_db; - - vacuum_all_databases(&cparams, &vacopts, - analyze_in_stages, - &objects, - concurrentCons, - progname, echo, quiet); - } - else - { - if (dbname == NULL) - { - if (getenv("PGDATABASE")) - dbname = getenv("PGDATABASE"); - else if (getenv("PGUSER")) - dbname = getenv("PGUSER"); - else - dbname = get_user_name_or_exit(progname); - } - - cparams.dbname = dbname; - - if (analyze_in_stages) - { - int stage; - SimpleStringList *found_objs = NULL; - - for (stage = 0; stage < ANALYZE_NUM_STAGES; stage++) - { - vacuum_one_database(&cparams, &vacopts, - stage, - &objects, - vacopts.missing_stats_only ? &found_objs : NULL, - concurrentCons, - progname, echo, quiet); - } - } - else - vacuum_one_database(&cparams, &vacopts, - ANALYZE_NO_STAGE, - &objects, NULL, - concurrentCons, - progname, echo, quiet); - } - - exit(0); + ret = vacuuming_main(&cparams, dbname, maintenance_db, &vacopts, + objfilter, &objects, tbl_count, analyze_in_stages, + concurrentCons, + progname, echo, quiet); + exit(ret); } /* * Verify that the filters used at command line are compatible. */ void -check_objfilter(void) +check_objfilter(VacObjFilter objfilter) { if ((objfilter & OBJFILTER_ALL_DBS) && (objfilter & OBJFILTER_DATABASE)) @@ -466,886 +335,6 @@ check_objfilter(void) pg_fatal("cannot vacuum all tables in schema(s) and exclude schema(s) at the same time"); } -/* - * Returns a newly malloc'd version of 'src' with escaped single quotes and - * backslashes. - */ -static char * -escape_quotes(const char *src) -{ - char *result = escape_single_quotes_ascii(src); - - if (!result) - pg_fatal("out of memory"); - return result; -} - -/* - * vacuum_one_database - * - * Process tables in the given database. - * - * There are two ways to specify the list of objects to process: - * - * 1) The "found_objs" parameter is a double pointer to a fully qualified list - * of objects to process, as returned by a previous call to - * vacuum_one_database(). - * - * a) If both "found_objs" (the double pointer) and "*found_objs" (the - * once-dereferenced double pointer) are not NULL, this list takes - * priority, and anything specified in "objects" is ignored. - * - * b) If "found_objs" (the double pointer) is not NULL but "*found_objs" - * (the once-dereferenced double pointer) _is_ NULL, the "objects" - * parameter takes priority, and the results of the catalog query - * described in (2) are stored in "found_objs". - * - * c) If "found_objs" (the double pointer) is NULL, the "objects" - * parameter again takes priority, and the results of the catalog query - * are not saved. - * - * 2) The "objects" parameter is a user-specified list of objects to process. - * When (1b) or (1c) applies, this function performs a catalog query to - * retrieve a fully qualified list of objects to process, as described - * below. - * - * a) If "objects" is not NULL, the catalog query gathers only the objects - * listed in "objects". - * - * b) If "objects" is NULL, all tables in the database are gathered. - * - * Note that this function is only concerned with running exactly one stage - * when in analyze-in-stages mode; caller must iterate on us if necessary. - * - * If concurrentCons is > 1, multiple connections are used to vacuum tables - * in parallel. - */ -static void -vacuum_one_database(ConnParams *cparams, - vacuumingOptions *vacopts, - int stage, - SimpleStringList *objects, - SimpleStringList **found_objs, - int concurrentCons, - const char *progname, bool echo, bool quiet) -{ - PQExpBufferData sql; - PGconn *conn; - SimpleStringListCell *cell; - ParallelSlotArray *sa; - int ntups = 0; - bool failed = false; - const char *initcmd; - SimpleStringList *ret = NULL; - const char *stage_commands[] = { - "SET default_statistics_target=1; SET vacuum_cost_delay=0;", - "SET default_statistics_target=10; RESET vacuum_cost_delay;", - "RESET default_statistics_target;" - }; - const char *stage_messages[] = { - gettext_noop("Generating minimal optimizer statistics (1 target)"), - gettext_noop("Generating medium optimizer statistics (10 targets)"), - gettext_noop("Generating default (full) optimizer statistics") - }; - - Assert(stage == ANALYZE_NO_STAGE || - (stage >= 0 && stage < ANALYZE_NUM_STAGES)); - - conn = connectDatabase(cparams, progname, echo, false, true); - - if (vacopts->disable_page_skipping && PQserverVersion(conn) < 90600) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "disable-page-skipping", "9.6"); - } - - if (vacopts->no_index_cleanup && PQserverVersion(conn) < 120000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "no-index-cleanup", "12"); - } - - if (vacopts->force_index_cleanup && PQserverVersion(conn) < 120000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "force-index-cleanup", "12"); - } - - if (!vacopts->do_truncate && PQserverVersion(conn) < 120000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "no-truncate", "12"); - } - - if (!vacopts->process_main && PQserverVersion(conn) < 160000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "no-process-main", "16"); - } - - if (!vacopts->process_toast && PQserverVersion(conn) < 140000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "no-process-toast", "14"); - } - - if (vacopts->skip_locked && PQserverVersion(conn) < 120000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "skip-locked", "12"); - } - - if (vacopts->min_xid_age != 0 && PQserverVersion(conn) < 90600) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "--min-xid-age", "9.6"); - } - - if (vacopts->min_mxid_age != 0 && PQserverVersion(conn) < 90600) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "--min-mxid-age", "9.6"); - } - - if (vacopts->parallel_workers >= 0 && PQserverVersion(conn) < 130000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "--parallel", "13"); - } - - if (vacopts->buffer_usage_limit && PQserverVersion(conn) < 160000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "--buffer-usage-limit", "16"); - } - - if (vacopts->missing_stats_only && PQserverVersion(conn) < 150000) - { - PQfinish(conn); - pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", - "--missing-stats-only", "15"); - } - - /* skip_database_stats is used automatically if server supports it */ - vacopts->skip_database_stats = (PQserverVersion(conn) >= 160000); - - if (!quiet) - { - if (stage != ANALYZE_NO_STAGE) - printf(_("%s: processing database \"%s\": %s\n"), - progname, PQdb(conn), _(stage_messages[stage])); - else - printf(_("%s: vacuuming database \"%s\"\n"), - progname, PQdb(conn)); - fflush(stdout); - } - - /* - * If the caller provided the results of a previous catalog query, just - * use that. Otherwise, run the catalog query ourselves and set the - * return variable if provided. - */ - if (found_objs && *found_objs) - ret = *found_objs; - else - { - ret = retrieve_objects(conn, vacopts, objects, echo); - if (found_objs) - *found_objs = ret; - } - - /* - * Count the number of objects in the catalog query result. If there are - * none, we are done. - */ - for (cell = ret ? ret->head : NULL; cell; cell = cell->next) - ntups++; - - if (ntups == 0) - { - PQfinish(conn); - return; - } - - /* - * Ensure concurrentCons is sane. If there are more connections than - * vacuumable relations, we don't need to use them all. - */ - if (concurrentCons > ntups) - concurrentCons = ntups; - if (concurrentCons <= 0) - concurrentCons = 1; - - /* - * All slots need to be prepared to run the appropriate analyze stage, if - * caller requested that mode. We have to prepare the initial connection - * ourselves before setting up the slots. - */ - if (stage == ANALYZE_NO_STAGE) - initcmd = NULL; - else - { - initcmd = stage_commands[stage]; - executeCommand(conn, initcmd, echo); - } - - /* - * Setup the database connections. We reuse the connection we already have - * for the first slot. If not in parallel mode, the first slot in the - * array contains the connection. - */ - sa = ParallelSlotsSetup(concurrentCons, cparams, progname, echo, initcmd); - ParallelSlotsAdoptConn(sa, conn); - - initPQExpBuffer(&sql); - - cell = ret->head; - do - { - const char *tabname = cell->val; - ParallelSlot *free_slot; - - if (CancelRequested) - { - failed = true; - goto finish; - } - - free_slot = ParallelSlotsGetIdle(sa, NULL); - if (!free_slot) - { - failed = true; - goto finish; - } - - prepare_vacuum_command(&sql, PQserverVersion(free_slot->connection), - vacopts, tabname); - - /* - * Execute the vacuum. All errors are handled in processQueryResult - * through ParallelSlotsGetIdle. - */ - ParallelSlotSetHandler(free_slot, TableCommandResultHandler, NULL); - run_vacuum_command(free_slot->connection, sql.data, - echo, tabname); - - cell = cell->next; - } while (cell != NULL); - - if (!ParallelSlotsWaitCompletion(sa)) - { - failed = true; - goto finish; - } - - /* If we used SKIP_DATABASE_STATS, mop up with ONLY_DATABASE_STATS */ - if (vacopts->skip_database_stats && stage == ANALYZE_NO_STAGE && - !vacopts->analyze_only) - { - const char *cmd = "VACUUM (ONLY_DATABASE_STATS);"; - ParallelSlot *free_slot = ParallelSlotsGetIdle(sa, NULL); - - if (!free_slot) - { - failed = true; - goto finish; - } - - ParallelSlotSetHandler(free_slot, TableCommandResultHandler, NULL); - run_vacuum_command(free_slot->connection, cmd, echo, NULL); - - if (!ParallelSlotsWaitCompletion(sa)) - failed = true; - } - -finish: - ParallelSlotsTerminate(sa); - pg_free(sa); - - termPQExpBuffer(&sql); - - if (failed) - exit(1); -} - -/* - * Prepare the list of tables to process by querying the catalogs. - * - * Since we execute the constructed query with the default search_path (which - * could be unsafe), everything in this query MUST be fully qualified. - * - * First, build a WITH clause for the catalog query if any tables were - * specified, with a set of values made of relation names and their optional - * set of columns. This is used to match any provided column lists with the - * generated qualified identifiers and to filter for the tables provided via - * --table. If a listed table does not exist, the catalog query will fail. - */ -static SimpleStringList * -retrieve_objects(PGconn *conn, vacuumingOptions *vacopts, - SimpleStringList *objects, bool echo) -{ - PQExpBufferData buf; - PQExpBufferData catalog_query; - PGresult *res; - SimpleStringListCell *cell; - SimpleStringList *found_objs = palloc0(sizeof(SimpleStringList)); - bool objects_listed = false; - - initPQExpBuffer(&catalog_query); - for (cell = objects ? objects->head : NULL; cell; cell = cell->next) - { - char *just_table = NULL; - const char *just_columns = NULL; - - if (!objects_listed) - { - appendPQExpBufferStr(&catalog_query, - "WITH listed_objects (object_oid, column_list) " - "AS (\n VALUES ("); - objects_listed = true; - } - else - appendPQExpBufferStr(&catalog_query, ",\n ("); - - if (objfilter & (OBJFILTER_SCHEMA | OBJFILTER_SCHEMA_EXCLUDE)) - { - appendStringLiteralConn(&catalog_query, cell->val, conn); - appendPQExpBufferStr(&catalog_query, "::pg_catalog.regnamespace, "); - } - - if (objfilter & OBJFILTER_TABLE) - { - /* - * Split relation and column names given by the user, this is used - * to feed the CTE with values on which are performed pre-run - * validity checks as well. For now these happen only on the - * relation name. - */ - splitTableColumnsSpec(cell->val, PQclientEncoding(conn), - &just_table, &just_columns); - - appendStringLiteralConn(&catalog_query, just_table, conn); - appendPQExpBufferStr(&catalog_query, "::pg_catalog.regclass, "); - } - - if (just_columns && just_columns[0] != '\0') - appendStringLiteralConn(&catalog_query, just_columns, conn); - else - appendPQExpBufferStr(&catalog_query, "NULL"); - - appendPQExpBufferStr(&catalog_query, "::pg_catalog.text)"); - - pg_free(just_table); - } - - /* Finish formatting the CTE */ - if (objects_listed) - appendPQExpBufferStr(&catalog_query, "\n)\n"); - - appendPQExpBufferStr(&catalog_query, "SELECT c.relname, ns.nspname"); - - if (objects_listed) - appendPQExpBufferStr(&catalog_query, ", listed_objects.column_list"); - - appendPQExpBufferStr(&catalog_query, - " FROM pg_catalog.pg_class c\n" - " JOIN pg_catalog.pg_namespace ns" - " ON c.relnamespace OPERATOR(pg_catalog.=) ns.oid\n" - " CROSS JOIN LATERAL (SELECT c.relkind IN (" - CppAsString2(RELKIND_PARTITIONED_TABLE) ", " - CppAsString2(RELKIND_PARTITIONED_INDEX) ")) as p (inherited)\n" - " LEFT JOIN pg_catalog.pg_class t" - " ON c.reltoastrelid OPERATOR(pg_catalog.=) t.oid\n"); - - /* - * Used to match the tables or schemas listed by the user, completing the - * JOIN clause. - */ - if (objects_listed) - { - appendPQExpBufferStr(&catalog_query, " LEFT JOIN listed_objects" - " ON listed_objects.object_oid" - " OPERATOR(pg_catalog.=) "); - - if (objfilter & OBJFILTER_TABLE) - appendPQExpBufferStr(&catalog_query, "c.oid\n"); - else - appendPQExpBufferStr(&catalog_query, "ns.oid\n"); - } - - /* - * Exclude temporary tables, beginning the WHERE clause. - */ - appendPQExpBufferStr(&catalog_query, - " WHERE c.relpersistence OPERATOR(pg_catalog.!=) " - CppAsString2(RELPERSISTENCE_TEMP) "\n"); - - /* - * Used to match the tables or schemas listed by the user, for the WHERE - * clause. - */ - if (objects_listed) - { - if (objfilter & OBJFILTER_SCHEMA_EXCLUDE) - appendPQExpBufferStr(&catalog_query, - " AND listed_objects.object_oid IS NULL\n"); - else - appendPQExpBufferStr(&catalog_query, - " AND listed_objects.object_oid IS NOT NULL\n"); - } - - /* - * If no tables were listed, filter for the relevant relation types. If - * tables were given via --table, don't bother filtering by relation type. - * Instead, let the server decide whether a given relation can be - * processed in which case the user will know about it. - */ - if ((objfilter & OBJFILTER_TABLE) == 0) - { - /* - * vacuumdb should generally follow the behavior of the underlying - * VACUUM and ANALYZE commands. If analyze_only is true, process - * regular tables, materialized views, and partitioned tables, just - * like ANALYZE (with no specific target tables) does. Otherwise, - * process only regular tables and materialized views, since VACUUM - * skips partitioned tables when no target tables are specified. - */ - if (vacopts->analyze_only) - appendPQExpBufferStr(&catalog_query, - " AND c.relkind OPERATOR(pg_catalog.=) ANY (array[" - CppAsString2(RELKIND_RELATION) ", " - CppAsString2(RELKIND_MATVIEW) ", " - CppAsString2(RELKIND_PARTITIONED_TABLE) "])\n"); - else - appendPQExpBufferStr(&catalog_query, - " AND c.relkind OPERATOR(pg_catalog.=) ANY (array[" - CppAsString2(RELKIND_RELATION) ", " - CppAsString2(RELKIND_MATVIEW) "])\n"); - - } - - /* - * For --min-xid-age and --min-mxid-age, the age of the relation is the - * greatest of the ages of the main relation and its associated TOAST - * table. The commands generated by vacuumdb will also process the TOAST - * table for the relation if necessary, so it does not need to be - * considered separately. - */ - if (vacopts->min_xid_age != 0) - { - appendPQExpBuffer(&catalog_query, - " AND GREATEST(pg_catalog.age(c.relfrozenxid)," - " pg_catalog.age(t.relfrozenxid)) " - " OPERATOR(pg_catalog.>=) '%d'::pg_catalog.int4\n" - " AND c.relfrozenxid OPERATOR(pg_catalog.!=)" - " '0'::pg_catalog.xid\n", - vacopts->min_xid_age); - } - - if (vacopts->min_mxid_age != 0) - { - appendPQExpBuffer(&catalog_query, - " AND GREATEST(pg_catalog.mxid_age(c.relminmxid)," - " pg_catalog.mxid_age(t.relminmxid)) OPERATOR(pg_catalog.>=)" - " '%d'::pg_catalog.int4\n" - " AND c.relminmxid OPERATOR(pg_catalog.!=)" - " '0'::pg_catalog.xid\n", - vacopts->min_mxid_age); - } - - if (vacopts->missing_stats_only) - { - appendPQExpBufferStr(&catalog_query, " AND (\n"); - - /* regular stats */ - appendPQExpBufferStr(&catalog_query, - " EXISTS (SELECT NULL FROM pg_catalog.pg_attribute a\n" - " WHERE a.attrelid OPERATOR(pg_catalog.=) c.oid\n" - " AND a.attnum OPERATOR(pg_catalog.>) 0::pg_catalog.int2\n" - " AND NOT a.attisdropped\n" - " AND a.attstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" - " AND a.attgenerated OPERATOR(pg_catalog.<>) " - CppAsString2(ATTRIBUTE_GENERATED_VIRTUAL) "\n" - " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic s\n" - " WHERE s.starelid OPERATOR(pg_catalog.=) a.attrelid\n" - " AND s.staattnum OPERATOR(pg_catalog.=) a.attnum\n" - " AND s.stainherit OPERATOR(pg_catalog.=) p.inherited))\n"); - - /* extended stats */ - appendPQExpBufferStr(&catalog_query, - " OR EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext e\n" - " WHERE e.stxrelid OPERATOR(pg_catalog.=) c.oid\n" - " AND e.stxstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" - " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext_data d\n" - " WHERE d.stxoid OPERATOR(pg_catalog.=) e.oid\n" - " AND d.stxdinherit OPERATOR(pg_catalog.=) p.inherited))\n"); - - /* expression indexes */ - appendPQExpBufferStr(&catalog_query, - " OR EXISTS (SELECT NULL FROM pg_catalog.pg_attribute a\n" - " JOIN pg_catalog.pg_index i" - " ON i.indexrelid OPERATOR(pg_catalog.=) a.attrelid\n" - " WHERE i.indrelid OPERATOR(pg_catalog.=) c.oid\n" - " AND i.indkey[a.attnum OPERATOR(pg_catalog.-) 1::pg_catalog.int2]" - " OPERATOR(pg_catalog.=) 0::pg_catalog.int2\n" - " AND a.attnum OPERATOR(pg_catalog.>) 0::pg_catalog.int2\n" - " AND NOT a.attisdropped\n" - " AND a.attstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" - " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic s\n" - " WHERE s.starelid OPERATOR(pg_catalog.=) a.attrelid\n" - " AND s.staattnum OPERATOR(pg_catalog.=) a.attnum\n" - " AND s.stainherit OPERATOR(pg_catalog.=) p.inherited))\n"); - - /* inheritance and regular stats */ - appendPQExpBufferStr(&catalog_query, - " OR EXISTS (SELECT NULL FROM pg_catalog.pg_attribute a\n" - " WHERE a.attrelid OPERATOR(pg_catalog.=) c.oid\n" - " AND a.attnum OPERATOR(pg_catalog.>) 0::pg_catalog.int2\n" - " AND NOT a.attisdropped\n" - " AND a.attstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" - " AND a.attgenerated OPERATOR(pg_catalog.<>) " - CppAsString2(ATTRIBUTE_GENERATED_VIRTUAL) "\n" - " AND c.relhassubclass\n" - " AND NOT p.inherited\n" - " AND EXISTS (SELECT NULL FROM pg_catalog.pg_inherits h\n" - " WHERE h.inhparent OPERATOR(pg_catalog.=) c.oid)\n" - " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic s\n" - " WHERE s.starelid OPERATOR(pg_catalog.=) a.attrelid\n" - " AND s.staattnum OPERATOR(pg_catalog.=) a.attnum\n" - " AND s.stainherit))\n"); - - /* inheritance and extended stats */ - appendPQExpBufferStr(&catalog_query, - " OR EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext e\n" - " WHERE e.stxrelid OPERATOR(pg_catalog.=) c.oid\n" - " AND e.stxstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" - " AND c.relhassubclass\n" - " AND NOT p.inherited\n" - " AND EXISTS (SELECT NULL FROM pg_catalog.pg_inherits h\n" - " WHERE h.inhparent OPERATOR(pg_catalog.=) c.oid)\n" - " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext_data d\n" - " WHERE d.stxoid OPERATOR(pg_catalog.=) e.oid\n" - " AND d.stxdinherit))\n"); - - appendPQExpBufferStr(&catalog_query, " )\n"); - } - - /* - * Execute the catalog query. We use the default search_path for this - * query for consistency with table lookups done elsewhere by the user. - */ - appendPQExpBufferStr(&catalog_query, " ORDER BY c.relpages DESC;"); - executeCommand(conn, "RESET search_path;", echo); - res = executeQuery(conn, catalog_query.data, echo); - termPQExpBuffer(&catalog_query); - PQclear(executeQuery(conn, ALWAYS_SECURE_SEARCH_PATH_SQL, echo)); - - /* - * Build qualified identifiers for each table, including the column list - * if given. - */ - initPQExpBuffer(&buf); - for (int i = 0; i < PQntuples(res); i++) - { - appendPQExpBufferStr(&buf, - fmtQualifiedIdEnc(PQgetvalue(res, i, 1), - PQgetvalue(res, i, 0), - PQclientEncoding(conn))); - - if (objects_listed && !PQgetisnull(res, i, 2)) - appendPQExpBufferStr(&buf, PQgetvalue(res, i, 2)); - - simple_string_list_append(found_objs, buf.data); - resetPQExpBuffer(&buf); - } - termPQExpBuffer(&buf); - PQclear(res); - - return found_objs; -} - -/* - * Vacuum/analyze all connectable databases. - * - * In analyze-in-stages mode, we process all databases in one stage before - * moving on to the next stage. That ensure minimal stats are available - * quickly everywhere before generating more detailed ones. - */ -static void -vacuum_all_databases(ConnParams *cparams, - vacuumingOptions *vacopts, - bool analyze_in_stages, - SimpleStringList *objects, - int concurrentCons, - const char *progname, bool echo, bool quiet) -{ - PGconn *conn; - PGresult *result; - int stage; - int i; - - conn = connectMaintenanceDatabase(cparams, progname, echo); - result = executeQuery(conn, - "SELECT datname FROM pg_database WHERE datallowconn AND datconnlimit <> -2 ORDER BY 1;", - echo); - PQfinish(conn); - - if (analyze_in_stages) - { - SimpleStringList **found_objs = NULL; - - if (vacopts->missing_stats_only) - found_objs = palloc0(PQntuples(result) * sizeof(SimpleStringList *)); - - /* - * When analyzing all databases in stages, we analyze them all in the - * fastest stage first, so that initial statistics become available - * for all of them as soon as possible. - * - * This means we establish several times as many connections, but - * that's a secondary consideration. - */ - for (stage = 0; stage < ANALYZE_NUM_STAGES; stage++) - { - for (i = 0; i < PQntuples(result); i++) - { - cparams->override_dbname = PQgetvalue(result, i, 0); - - vacuum_one_database(cparams, vacopts, - stage, - objects, - vacopts->missing_stats_only ? &found_objs[i] : NULL, - concurrentCons, - progname, echo, quiet); - } - } - } - else - { - for (i = 0; i < PQntuples(result); i++) - { - cparams->override_dbname = PQgetvalue(result, i, 0); - - vacuum_one_database(cparams, vacopts, - ANALYZE_NO_STAGE, - objects, NULL, - concurrentCons, - progname, echo, quiet); - } - } - - PQclear(result); -} - -/* - * Construct a vacuum/analyze command to run based on the given options, in the - * given string buffer, which may contain previous garbage. - * - * The table name used must be already properly quoted. The command generated - * depends on the server version involved and it is semicolon-terminated. - */ -static void -prepare_vacuum_command(PQExpBuffer sql, int serverVersion, - vacuumingOptions *vacopts, const char *table) -{ - const char *paren = " ("; - const char *comma = ", "; - const char *sep = paren; - - resetPQExpBuffer(sql); - - if (vacopts->analyze_only) - { - appendPQExpBufferStr(sql, "ANALYZE"); - - /* parenthesized grammar of ANALYZE is supported since v11 */ - if (serverVersion >= 110000) - { - if (vacopts->skip_locked) - { - /* SKIP_LOCKED is supported since v12 */ - Assert(serverVersion >= 120000); - appendPQExpBuffer(sql, "%sSKIP_LOCKED", sep); - sep = comma; - } - if (vacopts->verbose) - { - appendPQExpBuffer(sql, "%sVERBOSE", sep); - sep = comma; - } - if (vacopts->buffer_usage_limit) - { - Assert(serverVersion >= 160000); - appendPQExpBuffer(sql, "%sBUFFER_USAGE_LIMIT '%s'", sep, - vacopts->buffer_usage_limit); - sep = comma; - } - if (sep != paren) - appendPQExpBufferChar(sql, ')'); - } - else - { - if (vacopts->verbose) - appendPQExpBufferStr(sql, " VERBOSE"); - } - } - else - { - appendPQExpBufferStr(sql, "VACUUM"); - - /* parenthesized grammar of VACUUM is supported since v9.0 */ - if (serverVersion >= 90000) - { - if (vacopts->disable_page_skipping) - { - /* DISABLE_PAGE_SKIPPING is supported since v9.6 */ - Assert(serverVersion >= 90600); - appendPQExpBuffer(sql, "%sDISABLE_PAGE_SKIPPING", sep); - sep = comma; - } - if (vacopts->no_index_cleanup) - { - /* "INDEX_CLEANUP FALSE" has been supported since v12 */ - Assert(serverVersion >= 120000); - Assert(!vacopts->force_index_cleanup); - appendPQExpBuffer(sql, "%sINDEX_CLEANUP FALSE", sep); - sep = comma; - } - if (vacopts->force_index_cleanup) - { - /* "INDEX_CLEANUP TRUE" has been supported since v12 */ - Assert(serverVersion >= 120000); - Assert(!vacopts->no_index_cleanup); - appendPQExpBuffer(sql, "%sINDEX_CLEANUP TRUE", sep); - sep = comma; - } - if (!vacopts->do_truncate) - { - /* TRUNCATE is supported since v12 */ - Assert(serverVersion >= 120000); - appendPQExpBuffer(sql, "%sTRUNCATE FALSE", sep); - sep = comma; - } - if (!vacopts->process_main) - { - /* PROCESS_MAIN is supported since v16 */ - Assert(serverVersion >= 160000); - appendPQExpBuffer(sql, "%sPROCESS_MAIN FALSE", sep); - sep = comma; - } - if (!vacopts->process_toast) - { - /* PROCESS_TOAST is supported since v14 */ - Assert(serverVersion >= 140000); - appendPQExpBuffer(sql, "%sPROCESS_TOAST FALSE", sep); - sep = comma; - } - if (vacopts->skip_database_stats) - { - /* SKIP_DATABASE_STATS is supported since v16 */ - Assert(serverVersion >= 160000); - appendPQExpBuffer(sql, "%sSKIP_DATABASE_STATS", sep); - sep = comma; - } - if (vacopts->skip_locked) - { - /* SKIP_LOCKED is supported since v12 */ - Assert(serverVersion >= 120000); - appendPQExpBuffer(sql, "%sSKIP_LOCKED", sep); - sep = comma; - } - if (vacopts->full) - { - appendPQExpBuffer(sql, "%sFULL", sep); - sep = comma; - } - if (vacopts->freeze) - { - appendPQExpBuffer(sql, "%sFREEZE", sep); - sep = comma; - } - if (vacopts->verbose) - { - appendPQExpBuffer(sql, "%sVERBOSE", sep); - sep = comma; - } - if (vacopts->and_analyze) - { - appendPQExpBuffer(sql, "%sANALYZE", sep); - sep = comma; - } - if (vacopts->parallel_workers >= 0) - { - /* PARALLEL is supported since v13 */ - Assert(serverVersion >= 130000); - appendPQExpBuffer(sql, "%sPARALLEL %d", sep, - vacopts->parallel_workers); - sep = comma; - } - if (vacopts->buffer_usage_limit) - { - Assert(serverVersion >= 160000); - appendPQExpBuffer(sql, "%sBUFFER_USAGE_LIMIT '%s'", sep, - vacopts->buffer_usage_limit); - sep = comma; - } - if (sep != paren) - appendPQExpBufferChar(sql, ')'); - } - else - { - if (vacopts->full) - appendPQExpBufferStr(sql, " FULL"); - if (vacopts->freeze) - appendPQExpBufferStr(sql, " FREEZE"); - if (vacopts->verbose) - appendPQExpBufferStr(sql, " VERBOSE"); - if (vacopts->and_analyze) - appendPQExpBufferStr(sql, " ANALYZE"); - } - } - - appendPQExpBuffer(sql, " %s;", table); -} - -/* - * Send a vacuum/analyze command to the server, returning after sending the - * command. - * - * Any errors during command execution are reported to stderr. - */ -static void -run_vacuum_command(PGconn *conn, const char *sql, bool echo, - const char *table) -{ - bool status; - - if (echo) - printf("%s\n", sql); - - status = PQsendQuery(conn, sql) == 1; - - if (!status) - { - if (table) - pg_log_error("vacuuming of table \"%s\" in database \"%s\" failed: %s", - table, PQdb(conn), PQerrorMessage(conn)); - else - pg_log_error("vacuuming of database \"%s\" failed: %s", - PQdb(conn), PQerrorMessage(conn)); - } -} static void help(const char *progname) diff --git a/src/bin/scripts/vacuuming.c b/src/bin/scripts/vacuuming.c new file mode 100644 index 00000000000..b9f2e507557 --- /dev/null +++ b/src/bin/scripts/vacuuming.c @@ -0,0 +1,1012 @@ +/*------------------------------------------------------------------------- + * vacuuming.c + * Helper routines for vacuumdb + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/bin/scripts/vacuuming.c + * + *------------------------------------------------------------------------- + */ + +#include "postgres_fe.h" + +#include "catalog/pg_attribute_d.h" +#include "catalog/pg_class_d.h" +#include "common/connect.h" +#include "common/logging.h" +#include "fe_utils/cancel.h" +#include "fe_utils/option_utils.h" +#include "fe_utils/parallel_slot.h" +#include "fe_utils/query_utils.h" +#include "fe_utils/string_utils.h" +#include "vacuuming.h" + + +static int vacuum_one_database(ConnParams *cparams, + vacuumingOptions *vacopts, + int stage, + VacObjFilter objfilter, + SimpleStringList *objects, + SimpleStringList **found_objs, + int concurrentCons, + const char *progname, bool echo, bool quiet); +static int vacuum_all_databases(ConnParams *cparams, + vacuumingOptions *vacopts, + bool analyze_in_stages, + VacObjFilter objfilter, + SimpleStringList *objects, + int concurrentCons, + const char *progname, bool echo, bool quiet); +static SimpleStringList *retrieve_objects(PGconn *conn, + vacuumingOptions *vacopts, + VacObjFilter objfilter, + SimpleStringList *objects, + bool echo); +static void prepare_vacuum_command(PGconn *conn, PQExpBuffer sql, + vacuumingOptions *vacopts, const char *table); +static void run_vacuum_command(PGconn *conn, const char *sql, bool echo, + const char *table); + +/* + * Executes vacuum/analyze as indicated, or dies in case of failure. + */ +int +vacuuming_main(ConnParams *cparams, const char *dbname, + const char *maintenance_db, vacuumingOptions *vacopts, + VacObjFilter objfilter, SimpleStringList *objects, + int tbl_count, bool analyze_in_stages, int concurrentCons, + const char *progname, bool echo, bool quiet) +{ + setup_cancel_handler(NULL); + + /* Avoid opening extra connections. */ + if (tbl_count && (concurrentCons > tbl_count)) + concurrentCons = tbl_count; + + if (objfilter & OBJFILTER_ALL_DBS) + { + cparams->dbname = maintenance_db; + + return vacuum_all_databases(cparams, vacopts, + analyze_in_stages, + objfilter, objects, + concurrentCons, + progname, echo, quiet); + } + else + { + if (dbname == NULL) + { + if (getenv("PGDATABASE")) + dbname = getenv("PGDATABASE"); + else if (getenv("PGUSER")) + dbname = getenv("PGUSER"); + else + dbname = get_user_name_or_exit(progname); + } + + cparams->dbname = dbname; + + if (analyze_in_stages) + { + SimpleStringList *found_objs = NULL; + + for (int stage = 0; stage < ANALYZE_NUM_STAGES; stage++) + { + int ret; + + ret = vacuum_one_database(cparams, vacopts, + stage, + objfilter, objects, + vacopts->missing_stats_only ? &found_objs : NULL, + concurrentCons, + progname, echo, quiet); + if (ret != 0) + return ret; + } + + return EXIT_SUCCESS; + } + else + return vacuum_one_database(cparams, vacopts, + ANALYZE_NO_STAGE, + objfilter, objects, NULL, + concurrentCons, + progname, echo, quiet); + } +} + + +/* + * vacuum_one_database + * + * Process tables in the given database. + * + * There are two ways to specify the list of objects to process: + * + * 1) The "found_objs" parameter is a double pointer to a fully qualified list + * of objects to process, as returned by a previous call to + * vacuum_one_database(). + * + * a) If both "found_objs" (the double pointer) and "*found_objs" (the + * once-dereferenced double pointer) are not NULL, this list takes + * priority, and anything specified in "objects" is ignored. + * + * b) If "found_objs" (the double pointer) is not NULL but "*found_objs" + * (the once-dereferenced double pointer) _is_ NULL, the "objects" + * parameter takes priority, and the results of the catalog query + * described in (2) are stored in "found_objs". + * + * c) If "found_objs" (the double pointer) is NULL, the "objects" + * parameter again takes priority, and the results of the catalog query + * are not saved. + * + * 2) The "objects" parameter is a user-specified list of objects to process. + * When (1b) or (1c) applies, this function performs a catalog query to + * retrieve a fully qualified list of objects to process, as described + * below. + * + * a) If "objects" is not NULL, the catalog query gathers only the objects + * listed in "objects". + * + * b) If "objects" is NULL, all tables in the database are gathered. + * + * Note that this function is only concerned with running exactly one stage + * when in analyze-in-stages mode; caller must iterate on us if necessary. + * + * If concurrentCons is > 1, multiple connections are used to vacuum tables + * in parallel. + */ +static int +vacuum_one_database(ConnParams *cparams, + vacuumingOptions *vacopts, + int stage, + VacObjFilter objfilter, SimpleStringList *objects, + SimpleStringList **found_objs, + int concurrentCons, + const char *progname, bool echo, bool quiet) +{ + PQExpBufferData sql; + PGconn *conn; + SimpleStringListCell *cell; + ParallelSlotArray *sa; + int ntups = 0; + const char *initcmd; + SimpleStringList *retobjs = NULL; + int ret = EXIT_SUCCESS; + const char *stage_commands[] = { + "SET default_statistics_target=1; SET vacuum_cost_delay=0;", + "SET default_statistics_target=10; RESET vacuum_cost_delay;", + "RESET default_statistics_target;" + }; + const char *stage_messages[] = { + gettext_noop("Generating minimal optimizer statistics (1 target)"), + gettext_noop("Generating medium optimizer statistics (10 targets)"), + gettext_noop("Generating default (full) optimizer statistics") + }; + + Assert(stage == ANALYZE_NO_STAGE || + (stage >= 0 && stage < ANALYZE_NUM_STAGES)); + + conn = connectDatabase(cparams, progname, echo, false, true); + + if (vacopts->disable_page_skipping && PQserverVersion(conn) < 90600) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "disable-page-skipping", "9.6"); + } + + if (vacopts->no_index_cleanup && PQserverVersion(conn) < 120000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "no-index-cleanup", "12"); + } + + if (vacopts->force_index_cleanup && PQserverVersion(conn) < 120000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "force-index-cleanup", "12"); + } + + if (!vacopts->do_truncate && PQserverVersion(conn) < 120000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "no-truncate", "12"); + } + + if (!vacopts->process_main && PQserverVersion(conn) < 160000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "no-process-main", "16"); + } + + if (!vacopts->process_toast && PQserverVersion(conn) < 140000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "no-process-toast", "14"); + } + + if (vacopts->skip_locked && PQserverVersion(conn) < 120000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "skip-locked", "12"); + } + + if (vacopts->min_xid_age != 0 && PQserverVersion(conn) < 90600) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "--min-xid-age", "9.6"); + } + + if (vacopts->min_mxid_age != 0 && PQserverVersion(conn) < 90600) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "--min-mxid-age", "9.6"); + } + + if (vacopts->parallel_workers >= 0 && PQserverVersion(conn) < 130000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "--parallel", "13"); + } + + if (vacopts->buffer_usage_limit && PQserverVersion(conn) < 160000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "--buffer-usage-limit", "16"); + } + + if (vacopts->missing_stats_only && PQserverVersion(conn) < 150000) + { + PQfinish(conn); + pg_fatal("cannot use the \"%s\" option on server versions older than PostgreSQL %s", + "--missing-stats-only", "15"); + } + + /* skip_database_stats is used automatically if server supports it */ + vacopts->skip_database_stats = (PQserverVersion(conn) >= 160000); + + if (!quiet) + { + if (stage != ANALYZE_NO_STAGE) + printf(_("%s: processing database \"%s\": %s\n"), + progname, PQdb(conn), _(stage_messages[stage])); + else + printf(_("%s: vacuuming database \"%s\"\n"), + progname, PQdb(conn)); + fflush(stdout); + } + + /* + * If the caller provided the results of a previous catalog query, just + * use that. Otherwise, run the catalog query ourselves and set the + * return variable if provided. + */ + if (found_objs && *found_objs) + retobjs = *found_objs; + else + { + retobjs = retrieve_objects(conn, vacopts, objfilter, objects, echo); + if (found_objs) + *found_objs = retobjs; + } + + /* + * Count the number of objects in the catalog query result. If there are + * none, we are done. + */ + for (cell = retobjs ? retobjs->head : NULL; cell; cell = cell->next) + ntups++; + + if (ntups == 0) + { + PQfinish(conn); + return EXIT_SUCCESS; + } + + /* + * Ensure concurrentCons is sane. If there are more connections than + * vacuumable relations, we don't need to use them all. + */ + if (concurrentCons > ntups) + concurrentCons = ntups; + if (concurrentCons <= 0) + concurrentCons = 1; + + /* + * All slots need to be prepared to run the appropriate analyze stage, if + * caller requested that mode. We have to prepare the initial connection + * ourselves before setting up the slots. + */ + if (stage == ANALYZE_NO_STAGE) + initcmd = NULL; + else + { + initcmd = stage_commands[stage]; + executeCommand(conn, initcmd, echo); + } + + /* + * Setup the database connections. We reuse the connection we already have + * for the first slot. If not in parallel mode, the first slot in the + * array contains the connection. + */ + sa = ParallelSlotsSetup(concurrentCons, cparams, progname, echo, initcmd); + ParallelSlotsAdoptConn(sa, conn); + + initPQExpBuffer(&sql); + + cell = retobjs->head; + do + { + const char *tabname = cell->val; + ParallelSlot *free_slot; + + if (CancelRequested) + { + ret = EXIT_FAILURE; + goto finish; + } + + free_slot = ParallelSlotsGetIdle(sa, NULL); + if (!free_slot) + { + ret = EXIT_FAILURE; + goto finish; + } + + prepare_vacuum_command(free_slot->connection, &sql, + vacopts, tabname); + + /* + * Execute the vacuum. All errors are handled in processQueryResult + * through ParallelSlotsGetIdle. + */ + ParallelSlotSetHandler(free_slot, TableCommandResultHandler, NULL); + run_vacuum_command(free_slot->connection, sql.data, + echo, tabname); + + cell = cell->next; + } while (cell != NULL); + + if (!ParallelSlotsWaitCompletion(sa)) + { + ret = EXIT_FAILURE; + goto finish; + } + + /* If we used SKIP_DATABASE_STATS, mop up with ONLY_DATABASE_STATS */ + if (vacopts->skip_database_stats && stage == ANALYZE_NO_STAGE && + !vacopts->analyze_only) + { + const char *cmd = "VACUUM (ONLY_DATABASE_STATS);"; + ParallelSlot *free_slot = ParallelSlotsGetIdle(sa, NULL); + + if (!free_slot) + { + ret = EXIT_FAILURE; + goto finish; + } + + ParallelSlotSetHandler(free_slot, TableCommandResultHandler, NULL); + run_vacuum_command(free_slot->connection, cmd, echo, NULL); + + if (!ParallelSlotsWaitCompletion(sa)) + ret = EXIT_FAILURE; + } + +finish: + ParallelSlotsTerminate(sa); + pg_free(sa); + + termPQExpBuffer(&sql); + + return ret; +} + +/* + * Vacuum/analyze all connectable databases. + * + * In analyze-in-stages mode, we process all databases in one stage before + * moving on to the next stage. That ensure minimal stats are available + * quickly everywhere before generating more detailed ones. + */ +static int +vacuum_all_databases(ConnParams *cparams, + vacuumingOptions *vacopts, + bool analyze_in_stages, + VacObjFilter objfilter, + SimpleStringList *objects, + int concurrentCons, + const char *progname, bool echo, bool quiet) +{ + PGconn *conn; + PGresult *result; + + conn = connectMaintenanceDatabase(cparams, progname, echo); + result = executeQuery(conn, + "SELECT datname FROM pg_database WHERE datallowconn AND datconnlimit <> -2 ORDER BY 1;", + echo); + PQfinish(conn); + + if (analyze_in_stages) + { + SimpleStringList **found_objs = NULL; + + if (vacopts->missing_stats_only) + found_objs = palloc0(PQntuples(result) * sizeof(SimpleStringList *)); + + /* + * When analyzing all databases in stages, we analyze them all in the + * fastest stage first, so that initial statistics become available + * for all of them as soon as possible. + * + * This means we establish several times as many connections, but + * that's a secondary consideration. + */ + for (int stage = 0; stage < ANALYZE_NUM_STAGES; stage++) + { + for (int i = 0; i < PQntuples(result); i++) + { + int ret; + + cparams->override_dbname = PQgetvalue(result, i, 0); + ret = vacuum_one_database(cparams, vacopts, + stage, + objfilter, objects, + vacopts->missing_stats_only ? &found_objs[i] : NULL, + concurrentCons, + progname, echo, quiet); + if (ret != EXIT_SUCCESS) + return ret; + } + } + } + else + { + for (int i = 0; i < PQntuples(result); i++) + { + int ret; + + cparams->override_dbname = PQgetvalue(result, i, 0); + ret = vacuum_one_database(cparams, vacopts, + ANALYZE_NO_STAGE, + objfilter, objects, + NULL, + concurrentCons, + progname, echo, quiet); + if (ret != EXIT_SUCCESS) + return ret; + } + } + + PQclear(result); + + return EXIT_SUCCESS; +} + +/* + * Prepare the list of tables to process by querying the catalogs. + * + * Since we execute the constructed query with the default search_path (which + * could be unsafe), everything in this query MUST be fully qualified. + * + * First, build a WITH clause for the catalog query if any tables were + * specified, with a set of values made of relation names and their optional + * set of columns. This is used to match any provided column lists with the + * generated qualified identifiers and to filter for the tables provided via + * --table. If a listed table does not exist, the catalog query will fail. + */ +static SimpleStringList * +retrieve_objects(PGconn *conn, vacuumingOptions *vacopts, + VacObjFilter objfilter, SimpleStringList *objects, bool echo) +{ + PQExpBufferData buf; + PQExpBufferData catalog_query; + PGresult *res; + SimpleStringListCell *cell; + SimpleStringList *found_objs = palloc0(sizeof(SimpleStringList)); + bool objects_listed = false; + + initPQExpBuffer(&catalog_query); + for (cell = objects ? objects->head : NULL; cell; cell = cell->next) + { + char *just_table = NULL; + const char *just_columns = NULL; + + if (!objects_listed) + { + appendPQExpBufferStr(&catalog_query, + "WITH listed_objects (object_oid, column_list) AS (\n" + " VALUES ("); + objects_listed = true; + } + else + appendPQExpBufferStr(&catalog_query, ",\n ("); + + if (objfilter & (OBJFILTER_SCHEMA | OBJFILTER_SCHEMA_EXCLUDE)) + { + appendStringLiteralConn(&catalog_query, cell->val, conn); + appendPQExpBufferStr(&catalog_query, "::pg_catalog.regnamespace, "); + } + + if (objfilter & OBJFILTER_TABLE) + { + /* + * Split relation and column names given by the user, this is used + * to feed the CTE with values on which are performed pre-run + * validity checks as well. For now these happen only on the + * relation name. + */ + splitTableColumnsSpec(cell->val, PQclientEncoding(conn), + &just_table, &just_columns); + + appendStringLiteralConn(&catalog_query, just_table, conn); + appendPQExpBufferStr(&catalog_query, "::pg_catalog.regclass, "); + } + + if (just_columns && just_columns[0] != '\0') + appendStringLiteralConn(&catalog_query, just_columns, conn); + else + appendPQExpBufferStr(&catalog_query, "NULL"); + + appendPQExpBufferStr(&catalog_query, "::pg_catalog.text)"); + + pg_free(just_table); + } + + /* Finish formatting the CTE */ + if (objects_listed) + appendPQExpBufferStr(&catalog_query, "\n)\n"); + + appendPQExpBufferStr(&catalog_query, "SELECT c.relname, ns.nspname"); + + if (objects_listed) + appendPQExpBufferStr(&catalog_query, ", listed_objects.column_list"); + + appendPQExpBufferStr(&catalog_query, + " FROM pg_catalog.pg_class c\n" + " JOIN pg_catalog.pg_namespace ns" + " ON c.relnamespace OPERATOR(pg_catalog.=) ns.oid\n" + " CROSS JOIN LATERAL (SELECT c.relkind IN (" + CppAsString2(RELKIND_PARTITIONED_TABLE) ", " + CppAsString2(RELKIND_PARTITIONED_INDEX) ")) as p (inherited)\n" + " LEFT JOIN pg_catalog.pg_class t" + " ON c.reltoastrelid OPERATOR(pg_catalog.=) t.oid\n"); + + /* + * Used to match the tables or schemas listed by the user, completing the + * JOIN clause. + */ + if (objects_listed) + { + appendPQExpBufferStr(&catalog_query, " LEFT JOIN listed_objects" + " ON listed_objects.object_oid" + " OPERATOR(pg_catalog.=) "); + + if (objfilter & OBJFILTER_TABLE) + appendPQExpBufferStr(&catalog_query, "c.oid\n"); + else + appendPQExpBufferStr(&catalog_query, "ns.oid\n"); + } + + /* + * Exclude temporary tables, beginning the WHERE clause. + */ + appendPQExpBufferStr(&catalog_query, + " WHERE c.relpersistence OPERATOR(pg_catalog.!=) " + CppAsString2(RELPERSISTENCE_TEMP) "\n"); + + /* + * Used to match the tables or schemas listed by the user, for the WHERE + * clause. + */ + if (objects_listed) + { + if (objfilter & OBJFILTER_SCHEMA_EXCLUDE) + appendPQExpBufferStr(&catalog_query, + " AND listed_objects.object_oid IS NULL\n"); + else + appendPQExpBufferStr(&catalog_query, + " AND listed_objects.object_oid IS NOT NULL\n"); + } + + /* + * If no tables were listed, filter for the relevant relation types. If + * tables were given via --table, don't bother filtering by relation type. + * Instead, let the server decide whether a given relation can be + * processed in which case the user will know about it. + */ + if ((objfilter & OBJFILTER_TABLE) == 0) + { + /* + * vacuumdb should generally follow the behavior of the underlying + * VACUUM and ANALYZE commands. If analyze_only is true, process + * regular tables, materialized views, and partitioned tables, just + * like ANALYZE (with no specific target tables) does. Otherwise, + * process only regular tables and materialized views, since VACUUM + * skips partitioned tables when no target tables are specified. + */ + if (vacopts->analyze_only) + appendPQExpBufferStr(&catalog_query, + " AND c.relkind OPERATOR(pg_catalog.=) ANY (array[" + CppAsString2(RELKIND_RELATION) ", " + CppAsString2(RELKIND_MATVIEW) ", " + CppAsString2(RELKIND_PARTITIONED_TABLE) "])\n"); + else + appendPQExpBufferStr(&catalog_query, + " AND c.relkind OPERATOR(pg_catalog.=) ANY (array[" + CppAsString2(RELKIND_RELATION) ", " + CppAsString2(RELKIND_MATVIEW) "])\n"); + } + + /* + * For --min-xid-age and --min-mxid-age, the age of the relation is the + * greatest of the ages of the main relation and its associated TOAST + * table. The commands generated by vacuumdb will also process the TOAST + * table for the relation if necessary, so it does not need to be + * considered separately. + */ + if (vacopts->min_xid_age != 0) + { + appendPQExpBuffer(&catalog_query, + " AND GREATEST(pg_catalog.age(c.relfrozenxid)," + " pg_catalog.age(t.relfrozenxid)) " + " OPERATOR(pg_catalog.>=) '%d'::pg_catalog.int4\n" + " AND c.relfrozenxid OPERATOR(pg_catalog.!=)" + " '0'::pg_catalog.xid\n", + vacopts->min_xid_age); + } + + if (vacopts->min_mxid_age != 0) + { + appendPQExpBuffer(&catalog_query, + " AND GREATEST(pg_catalog.mxid_age(c.relminmxid)," + " pg_catalog.mxid_age(t.relminmxid)) OPERATOR(pg_catalog.>=)" + " '%d'::pg_catalog.int4\n" + " AND c.relminmxid OPERATOR(pg_catalog.!=)" + " '0'::pg_catalog.xid\n", + vacopts->min_mxid_age); + } + + if (vacopts->missing_stats_only) + { + appendPQExpBufferStr(&catalog_query, " AND (\n"); + + /* regular stats */ + appendPQExpBufferStr(&catalog_query, + " EXISTS (SELECT NULL FROM pg_catalog.pg_attribute a\n" + " WHERE a.attrelid OPERATOR(pg_catalog.=) c.oid\n" + " AND a.attnum OPERATOR(pg_catalog.>) 0::pg_catalog.int2\n" + " AND NOT a.attisdropped\n" + " AND a.attstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" + " AND a.attgenerated OPERATOR(pg_catalog.<>) " + CppAsString2(ATTRIBUTE_GENERATED_VIRTUAL) "\n" + " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic s\n" + " WHERE s.starelid OPERATOR(pg_catalog.=) a.attrelid\n" + " AND s.staattnum OPERATOR(pg_catalog.=) a.attnum\n" + " AND s.stainherit OPERATOR(pg_catalog.=) p.inherited))\n"); + + /* extended stats */ + appendPQExpBufferStr(&catalog_query, + " OR EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext e\n" + " WHERE e.stxrelid OPERATOR(pg_catalog.=) c.oid\n" + " AND e.stxstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" + " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext_data d\n" + " WHERE d.stxoid OPERATOR(pg_catalog.=) e.oid\n" + " AND d.stxdinherit OPERATOR(pg_catalog.=) p.inherited))\n"); + + /* expression indexes */ + appendPQExpBufferStr(&catalog_query, + " OR EXISTS (SELECT NULL FROM pg_catalog.pg_attribute a\n" + " JOIN pg_catalog.pg_index i" + " ON i.indexrelid OPERATOR(pg_catalog.=) a.attrelid\n" + " WHERE i.indrelid OPERATOR(pg_catalog.=) c.oid\n" + " AND i.indkey[a.attnum OPERATOR(pg_catalog.-) 1::pg_catalog.int2]" + " OPERATOR(pg_catalog.=) 0::pg_catalog.int2\n" + " AND a.attnum OPERATOR(pg_catalog.>) 0::pg_catalog.int2\n" + " AND NOT a.attisdropped\n" + " AND a.attstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" + " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic s\n" + " WHERE s.starelid OPERATOR(pg_catalog.=) a.attrelid\n" + " AND s.staattnum OPERATOR(pg_catalog.=) a.attnum\n" + " AND s.stainherit OPERATOR(pg_catalog.=) p.inherited))\n"); + + /* inheritance and regular stats */ + appendPQExpBufferStr(&catalog_query, + " OR EXISTS (SELECT NULL FROM pg_catalog.pg_attribute a\n" + " WHERE a.attrelid OPERATOR(pg_catalog.=) c.oid\n" + " AND a.attnum OPERATOR(pg_catalog.>) 0::pg_catalog.int2\n" + " AND NOT a.attisdropped\n" + " AND a.attstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" + " AND a.attgenerated OPERATOR(pg_catalog.<>) " + CppAsString2(ATTRIBUTE_GENERATED_VIRTUAL) "\n" + " AND c.relhassubclass\n" + " AND NOT p.inherited\n" + " AND EXISTS (SELECT NULL FROM pg_catalog.pg_inherits h\n" + " WHERE h.inhparent OPERATOR(pg_catalog.=) c.oid)\n" + " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic s\n" + " WHERE s.starelid OPERATOR(pg_catalog.=) a.attrelid\n" + " AND s.staattnum OPERATOR(pg_catalog.=) a.attnum\n" + " AND s.stainherit))\n"); + + /* inheritance and extended stats */ + appendPQExpBufferStr(&catalog_query, + " OR EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext e\n" + " WHERE e.stxrelid OPERATOR(pg_catalog.=) c.oid\n" + " AND e.stxstattarget IS DISTINCT FROM 0::pg_catalog.int2\n" + " AND c.relhassubclass\n" + " AND NOT p.inherited\n" + " AND EXISTS (SELECT NULL FROM pg_catalog.pg_inherits h\n" + " WHERE h.inhparent OPERATOR(pg_catalog.=) c.oid)\n" + " AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_statistic_ext_data d\n" + " WHERE d.stxoid OPERATOR(pg_catalog.=) e.oid\n" + " AND d.stxdinherit))\n"); + + appendPQExpBufferStr(&catalog_query, " )\n"); + } + + /* + * Execute the catalog query. We use the default search_path for this + * query for consistency with table lookups done elsewhere by the user. + */ + appendPQExpBufferStr(&catalog_query, " ORDER BY c.relpages DESC;"); + executeCommand(conn, "RESET search_path;", echo); + res = executeQuery(conn, catalog_query.data, echo); + termPQExpBuffer(&catalog_query); + PQclear(executeQuery(conn, ALWAYS_SECURE_SEARCH_PATH_SQL, echo)); + + /* + * Build qualified identifiers for each table, including the column list + * if given. + */ + initPQExpBuffer(&buf); + for (int i = 0; i < PQntuples(res); i++) + { + appendPQExpBufferStr(&buf, + fmtQualifiedIdEnc(PQgetvalue(res, i, 1), + PQgetvalue(res, i, 0), + PQclientEncoding(conn))); + + if (objects_listed && !PQgetisnull(res, i, 2)) + appendPQExpBufferStr(&buf, PQgetvalue(res, i, 2)); + + simple_string_list_append(found_objs, buf.data); + resetPQExpBuffer(&buf); + } + termPQExpBuffer(&buf); + PQclear(res); + + return found_objs; +} + +/* + * Construct a vacuum/analyze command to run based on the given + * options, in the given string buffer, which may contain previous garbage. + * + * The table name used must be already properly quoted. The command generated + * depends on the server version involved and it is semicolon-terminated. + */ +static void +prepare_vacuum_command(PGconn *conn, PQExpBuffer sql, + vacuumingOptions *vacopts, const char *table) +{ + int serverVersion = PQserverVersion(conn); + const char *paren = " ("; + const char *comma = ", "; + const char *sep = paren; + + resetPQExpBuffer(sql); + + if (vacopts->analyze_only) + { + appendPQExpBufferStr(sql, "ANALYZE"); + + /* parenthesized grammar of ANALYZE is supported since v11 */ + if (serverVersion >= 110000) + { + if (vacopts->skip_locked) + { + /* SKIP_LOCKED is supported since v12 */ + Assert(serverVersion >= 120000); + appendPQExpBuffer(sql, "%sSKIP_LOCKED", sep); + sep = comma; + } + if (vacopts->verbose) + { + appendPQExpBuffer(sql, "%sVERBOSE", sep); + sep = comma; + } + if (vacopts->buffer_usage_limit) + { + Assert(serverVersion >= 160000); + appendPQExpBuffer(sql, "%sBUFFER_USAGE_LIMIT '%s'", sep, + vacopts->buffer_usage_limit); + sep = comma; + } + if (sep != paren) + appendPQExpBufferChar(sql, ')'); + } + else + { + if (vacopts->verbose) + appendPQExpBufferStr(sql, " VERBOSE"); + } + } + else + { + appendPQExpBufferStr(sql, "VACUUM"); + + /* parenthesized grammar of VACUUM is supported since v9.0 */ + if (serverVersion >= 90000) + { + if (vacopts->disable_page_skipping) + { + /* DISABLE_PAGE_SKIPPING is supported since v9.6 */ + Assert(serverVersion >= 90600); + appendPQExpBuffer(sql, "%sDISABLE_PAGE_SKIPPING", sep); + sep = comma; + } + if (vacopts->no_index_cleanup) + { + /* "INDEX_CLEANUP FALSE" has been supported since v12 */ + Assert(serverVersion >= 120000); + Assert(!vacopts->force_index_cleanup); + appendPQExpBuffer(sql, "%sINDEX_CLEANUP FALSE", sep); + sep = comma; + } + if (vacopts->force_index_cleanup) + { + /* "INDEX_CLEANUP TRUE" has been supported since v12 */ + Assert(serverVersion >= 120000); + Assert(!vacopts->no_index_cleanup); + appendPQExpBuffer(sql, "%sINDEX_CLEANUP TRUE", sep); + sep = comma; + } + if (!vacopts->do_truncate) + { + /* TRUNCATE is supported since v12 */ + Assert(serverVersion >= 120000); + appendPQExpBuffer(sql, "%sTRUNCATE FALSE", sep); + sep = comma; + } + if (!vacopts->process_main) + { + /* PROCESS_MAIN is supported since v16 */ + Assert(serverVersion >= 160000); + appendPQExpBuffer(sql, "%sPROCESS_MAIN FALSE", sep); + sep = comma; + } + if (!vacopts->process_toast) + { + /* PROCESS_TOAST is supported since v14 */ + Assert(serverVersion >= 140000); + appendPQExpBuffer(sql, "%sPROCESS_TOAST FALSE", sep); + sep = comma; + } + if (vacopts->skip_database_stats) + { + /* SKIP_DATABASE_STATS is supported since v16 */ + Assert(serverVersion >= 160000); + appendPQExpBuffer(sql, "%sSKIP_DATABASE_STATS", sep); + sep = comma; + } + if (vacopts->skip_locked) + { + /* SKIP_LOCKED is supported since v12 */ + Assert(serverVersion >= 120000); + appendPQExpBuffer(sql, "%sSKIP_LOCKED", sep); + sep = comma; + } + if (vacopts->full) + { + appendPQExpBuffer(sql, "%sFULL", sep); + sep = comma; + } + if (vacopts->freeze) + { + appendPQExpBuffer(sql, "%sFREEZE", sep); + sep = comma; + } + if (vacopts->verbose) + { + appendPQExpBuffer(sql, "%sVERBOSE", sep); + sep = comma; + } + if (vacopts->and_analyze) + { + appendPQExpBuffer(sql, "%sANALYZE", sep); + sep = comma; + } + if (vacopts->parallel_workers >= 0) + { + /* PARALLEL is supported since v13 */ + Assert(serverVersion >= 130000); + appendPQExpBuffer(sql, "%sPARALLEL %d", sep, + vacopts->parallel_workers); + sep = comma; + } + if (vacopts->buffer_usage_limit) + { + Assert(serverVersion >= 160000); + appendPQExpBuffer(sql, "%sBUFFER_USAGE_LIMIT '%s'", sep, + vacopts->buffer_usage_limit); + sep = comma; + } + if (sep != paren) + appendPQExpBufferChar(sql, ')'); + } + else + { + if (vacopts->full) + appendPQExpBufferStr(sql, " FULL"); + if (vacopts->freeze) + appendPQExpBufferStr(sql, " FREEZE"); + if (vacopts->verbose) + appendPQExpBufferStr(sql, " VERBOSE"); + if (vacopts->and_analyze) + appendPQExpBufferStr(sql, " ANALYZE"); + } + } + + appendPQExpBuffer(sql, " %s;", table); +} + +/* + * Send a vacuum/analyze command to the server, returning after sending the + * command. + * + * Any errors during command execution are reported to stderr. + */ +static void +run_vacuum_command(PGconn *conn, const char *sql, bool echo, + const char *table) +{ + bool status; + + if (echo) + printf("%s\n", sql); + + status = PQsendQuery(conn, sql) == 1; + + if (!status) + { + if (table) + { + pg_log_error("vacuuming of table \"%s\" in database \"%s\" failed: %s", + table, PQdb(conn), PQerrorMessage(conn)); + } + else + { + pg_log_error("vacuuming of database \"%s\" failed: %s", + PQdb(conn), PQerrorMessage(conn)); + } + } +} + +/* + * Returns a newly malloc'd version of 'src' with escaped single quotes and + * backslashes. + */ +char * +escape_quotes(const char *src) +{ + char *result = escape_single_quotes_ascii(src); + + if (!result) + pg_fatal("out of memory"); + return result; +} diff --git a/src/bin/scripts/vacuuming.h b/src/bin/scripts/vacuuming.h new file mode 100644 index 00000000000..021953e153a --- /dev/null +++ b/src/bin/scripts/vacuuming.h @@ -0,0 +1,68 @@ +/*------------------------------------------------------------------------- + * + * vacuuming.h + * Common declarations for vacuuming.c + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/bin/scripts/vacuuming.h + * + *------------------------------------------------------------------------- + */ +#ifndef VACUUMING_H +#define VACUUMING_H + +#include "common.h" +#include "fe_utils/connect_utils.h" +#include "fe_utils/simple_list.h" + +/* For analyze-in-stages mode */ +#define ANALYZE_NO_STAGE -1 +#define ANALYZE_NUM_STAGES 3 + +/* vacuum options controlled by user flags */ +typedef struct vacuumingOptions +{ + bool analyze_only; + bool verbose; + bool and_analyze; + bool full; + bool freeze; + bool disable_page_skipping; + bool skip_locked; + int min_xid_age; + int min_mxid_age; + int parallel_workers; /* >= 0 indicates user specified the + * parallel degree, otherwise -1 */ + bool no_index_cleanup; + bool force_index_cleanup; + bool do_truncate; + bool process_main; + bool process_toast; + bool skip_database_stats; + char *buffer_usage_limit; + bool missing_stats_only; +} vacuumingOptions; + +/* object filter options */ +typedef enum +{ + OBJFILTER_NONE = 0, /* no filter used */ + OBJFILTER_ALL_DBS = (1 << 0), /* -a | --all */ + OBJFILTER_DATABASE = (1 << 1), /* -d | --dbname */ + OBJFILTER_TABLE = (1 << 2), /* -t | --table */ + OBJFILTER_SCHEMA = (1 << 3), /* -n | --schema */ + OBJFILTER_SCHEMA_EXCLUDE = (1 << 4), /* -N | --exclude-schema */ +} VacObjFilter; + +extern int vacuuming_main(ConnParams *cparams, const char *dbname, + const char *maintenance_db, vacuumingOptions *vacopts, + VacObjFilter objfilter, SimpleStringList *objects, + int tbl_count, bool analyze_in_stages, + int concurrentCons, + const char *progname, bool echo, bool quiet); + +extern char *escape_quotes(const char *src); + +#endif /* VACUUMING_H */ base-commit: e849bd551c323a384f2b14d20a1b7bfaa6127ed7 -- 2.47.3 --52vaejy5wnlkvc5v Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename="v22-0002-Add-REPACK-command.patch" ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). @ 2026-06-16 06:49 ChangAo Chen <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw) When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index faa07d1a118..2879c8af574 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.47.3 --op6mnexl7cn72cto Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename=v2-0002-fixups.patch ^ permalink raw reply [nested|flat] 108+ messages in thread
* Do not lock tables in get_tables_to_repack @ 2026-06-16 07:34 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 0 siblings, 2 replies; 108+ messages in thread From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-06-16 07:34 UTC (permalink / raw) To: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]> Hi hackers, When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). Thoughts? -- Regards, ChangAo Chen Attachments: [application/octet-stream] v1-0001-Do-not-lock-tables-in-get_tables_to_repack.patch (5.4K, ../../[email protected]/2-v1-0001-Do-not-lock-tables-in-get_tables_to_repack.patch) download | inline diff: From fa5c3073f2f41cf3c8ab7c9663b681e6140a4824 Mon Sep 17 00:00:00 2001 From: ChangAo Chen <[email protected]> Date: Tue, 16 Jun 2026 14:49:49 +0800 Subject: [PATCH v1] Do not lock tables in get_tables_to_repack(). When doing a whole database repack, we build a list of repackable tables and take a lock on them to prevent concurrent drops. But concurrent drops can always happen after we build the list because we process each table in a separate transaction. The ConditionalLockRelationOid() also makes the default behavior like SKIP_LOCKED, which is unexpected. To remove the locks, we need to make repack_is_permitted_for_relation() handles concurrent drops correctly: it should not report an error when failing to search the syscache in pg_class_aclcheck(). Use pg_class_aclcheck_ext() instead to detect a concurrent drop. Also check the return value of get_rel_name(). While at it, replace relation_close() with table_close() to match the table_open(). --- src/backend/commands/repack.c | 67 ++++++++++------------------------- 1 file changed, 19 insertions(+), 48 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index ec100e3eef5..6f25effeed2 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -2159,22 +2159,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) index = (Form_pg_index) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the index's table, to ensure it - * doesn't go away while we collect the list. If we cannot, just - * disregard it. Be sure to release this if we ultimately decide - * not to process the table! - */ - if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock)) - continue; - - /* Verify that the table still exists; skip if not */ classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); if (!HeapTupleIsValid(classtup)) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } classForm = (Form_pg_class) GETSTRUCT(classtup); /* Skip temp relations belonging to other sessions */ @@ -2182,7 +2169,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) !isTempOrTempToastNamespace(classForm->relnamespace)) { ReleaseSysCache(classtup); - UnlockRelationOid(index->indrelid, AccessShareLock); continue; } @@ -2191,10 +2177,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, GetUserId())) - { - UnlockRelationOid(index->indrelid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2218,45 +2201,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) class = (Form_pg_class) GETSTRUCT(tuple); - /* - * Try to obtain a light lock on the table, to ensure it doesn't - * go away while we collect the list. If we cannot, just - * disregard the table. Be sure to release this if we ultimately - * decide not to process the table! - */ - if (!ConditionalLockRelationOid(class->oid, AccessShareLock)) - continue; - - /* Verify that the table still exists */ - if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid))) - { - UnlockRelationOid(class->oid, AccessShareLock); - continue; - } - /* Can only process plain tables and matviews */ if (class->relkind != RELKIND_RELATION && class->relkind != RELKIND_MATVIEW) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Skip temp relations belonging to other sessions */ if (class->relpersistence == RELPERSISTENCE_TEMP && !isTempOrTempToastNamespace(class->relnamespace)) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, GetUserId())) - { - UnlockRelationOid(class->oid, AccessShareLock); continue; - } /* Use a permanent memory context for the result list */ oldcxt = MemoryContextSwitchTo(permcxt); @@ -2269,7 +2227,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) } table_endscan(scan); - relation_close(catalog, AccessShareLock); + table_close(catalog, AccessShareLock); return rtcs; } @@ -2347,15 +2305,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) { + bool is_missing = false; + Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK) + if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK) return true; - ereport(WARNING, - errmsg("permission denied to execute %s on \"%s\", skipping it", - RepackCommandAsString(cmd), - get_rel_name(relid))); + /* Report a warning if the relation still exists. */ + if (!is_missing) + { + char *relname; + + relname = get_rel_name(relid); + if (relname != NULL) + { + ereport(WARNING, + errmsg("permission denied to execute %s on \"%s\", skipping it", + RepackCommandAsString(cmd), relname)); + + pfree(relname); + } + } return false; } -- 2.34.1 ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-06-27 19:56 Bharath Rupireddy <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 1 sibling, 0 replies; 108+ messages in thread From: Bharath Rupireddy @ 2026-06-27 19:56 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]>; Antonin Houska <[email protected]>; Alvaro Herrera <[email protected]> Hi, On Tue, Jun 16, 2026 at 12:35 AM cca5507 <[email protected]> wrote: > > Hi hackers, > > When doing a whole database repack, we build a list of repackable > tables and take a lock on them to prevent concurrent drops. But > concurrent drops can always happen after we build the list because > we process each table in a separate transaction. The > ConditionalLockRelationOid() also makes the default behavior like > SKIP_LOCKED, which is unexpected. > > To remove the locks, we need to make repack_is_permitted_for_relation() > handles concurrent drops correctly: it should not report an error > when failing to search the syscache in pg_class_aclcheck(). Use > pg_class_aclcheck_ext() instead to detect a concurrent drop. Also > check the return value of get_rel_name(). > > Thoughts? I don't have a strong opinion on fixing this for REPACK. For vacuum, we wanted to get consistent behavior across all modes of invoking it [1]. Whether to handle concurrent drops for REPACK depends on how long it spends scanning pg_index/pg_class in get_tables_to_repack. Also, vacuum is more commonly run database-wide (against all tables), and without field experience showing this is a real problem for REPACK, I'm not sure the fix is needed. That said, others may have a different take - adding the REPACK authors here for their input. [1] https://www.postgresql.org/message-id/CALj2ACUbhDFJWSwiyoUxXED2S2fr9Xis%3D08Rnjq53UzBE4FvzA%40mail.g... -- Bharath Rupireddy Amazon Web Services: https://aws.amazon.com ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-07 16:53 Álvaro Herrera <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 1 sibling, 1 reply; 108+ messages in thread From: Álvaro Herrera @ 2026-07-07 16:53 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]> On 2026-Jun-16, cca5507 wrote: > Hi hackers, > > When doing a whole database repack, we build a list of repackable > tables and take a lock on them to prevent concurrent drops. But > concurrent drops can always happen after we build the list because > we process each table in a separate transaction. Not only that. We have actually three ways to obtain the list of tables to repack, and only one of these obtains the locks. So this code is internally inconsistent. I agree that we should do something like your patch. I wanted to be a little more defensive though; how about the attached? -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-08 02:36 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> parent: Álvaro Herrera <[email protected]> 0 siblings, 1 reply; 108+ messages in thread From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-07-08 02:36 UTC (permalink / raw) To: =?utf-8?B?w4FsdmFybyBIZXJyZXJh?= <[email protected]>; +Cc: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]> > > Hi hackers, > > > > When doing a whole database repack, we build a list of repackable > > tables and take a lock on them to prevent concurrent drops. But > > concurrent drops can always happen after we build the list because > > we process each table in a separate transaction. > > Not only that. We have actually three ways to obtain the list of tables > to repack, and only one of these obtains the locks. So this code is > internally inconsistent. I agree that we should do something like your > patch. I wanted to be a little more defensive though; how about the > attached? - classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); + classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid)); Do we really need to copy it? We hold a refcount on it so it won't be freed until we release it. Otherwise LGTM. -- Regards, ChangAo Chen ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-10 14:22 Álvaro Herrera <[email protected]> parent: =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 0 siblings, 1 reply; 108+ messages in thread From: Álvaro Herrera @ 2026-07-10 14:22 UTC (permalink / raw) To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]> On 2026-Jul-08, cca5507 wrote: > - classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); > + classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid)); > > Do we really need to copy it? We hold a refcount on it so it won't be freed > until we release it. Otherwise LGTM. Yeah, I guess it doesn't matter. I have removed the copy and updated some comments. I also realized that there are some places where we weren't dealing correctly with the possibility that the relation goes away, or is replaced with something different, so I added that too. While looking at it I also realized that get_tables_to_repack_partitioned is likewise not careful enough about it: we do IndexGetRelation(, false) which fails hard if the pg_index tuple cannot be found, which is the wrong thing to do. At the same time, it's annoying that half of the code that clearly belongs in that routine is actually in ExecRepack(). I moved that to where it rightfully belongs. (The only somewhat annoying thing is that we have to NULL-out the Relation pointer after returning; but that's not *too* bad IMO.) Any opinions on this? -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ "No me acuerdo, pero no es cierto. No es cierto, y si fuera cierto, no me acuerdo." (Augusto Pinochet a una corte de justicia) ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-10 16:03 Bharath Rupireddy <[email protected]> parent: Álvaro Herrera <[email protected]> 0 siblings, 1 reply; 108+ messages in thread From: Bharath Rupireddy @ 2026-07-10 16:03 UTC (permalink / raw) To: Álvaro Herrera <[email protected]>; +Cc: cca5507 <[email protected]>; pgsql-hackers <[email protected]> Hi, On Fri, Jul 10, 2026 at 7:22 AM Álvaro Herrera <[email protected]> wrote: > > On 2026-Jul-08, cca5507 wrote: > > > - classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid)); > > + classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid)); > > > > Do we really need to copy it? We hold a refcount on it so it won't be freed > > until we release it. Otherwise LGTM. Thanks for committing this. Here is my overall take. Even before this commit, a database-wide REPACK does not error on a concurrently dropped table. get_tables_to_repack takes a brief lock on each table before the ACL check, which blocks a concurrent drop while the list is being built. Later each table is re-opened under its lock and skipped if it is already gone. So the brief lock is not needed for correctness. What it does is let an unprivileged user lock relations it may not even be allowed to repack, including system catalogs, before we have checked its privileges. I am fine with removing the lock as the commit did. I would also like to tighten repack_is_permitted_for_relation so a caller that holds a lock still errors out on a missing relation instead of skipping it silently (https://www.postgresql.org/message-id/akPhEffRipH4isWF%40nathan). Attached as a follow-up patch. Please have a look. > Yeah, I guess it doesn't matter. I have removed the copy and updated > some comments. I also realized that there are some places where we > weren't dealing correctly with the possibility that the relation goes > away, or is replaced with something different, so I added that too. I agree that the SearchSysCacheCopy1 in v2-0002 adds no benefit. Since no lock is held on the relation, there is no point in copying the syscache tuple. > While looking at it I also realized that get_tables_to_repack_partitioned > is likewise not careful enough about it: we do IndexGetRelation(, false) > which fails hard if the pg_index tuple cannot be found, which is the > wrong thing to do. > > At the same time, it's annoying that half of the code that clearly > belongs in that routine is actually in ExecRepack(). I moved that to > where it rightfully belongs. (The only somewhat annoying thing is that > we have to NULL-out the Relation pointer after returning; but that's not > *too* bad IMO.) > > Any opinions on this? I will take a closer look at this in a bit. -- Bharath Rupireddy Amazon Web Services: https://aws.amazon.com Attachments: [application/octet-stream] v1-0001-Tighten-ACL-check-in-repack_is_permitted_for_rela.patch (5.1K, ../../CALj2ACX3pyuRS8++6L20cJUMRTf_qbbVp69J1btJ3y6=77e5gw@mail.gmail.com/2-v1-0001-Tighten-ACL-check-in-repack_is_permitted_for_rela.patch) download | inline diff: From 6729b2f14ed623a8b38f5a530b8c85c96bfd5b40 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy <[email protected]> Date: Fri, 10 Jul 2026 15:42:47 +0000 Subject: [PATCH v1] Tighten ACL check in repack_is_permitted_for_relation() Commit c71d43025d7 made repack_is_permitted_for_relation() use _ext() and skip a concurrently dropped relation silently. That is fine for the callers that hold no lock on the relation, but it is applied unconditionally, including where we may already hold a lock on the relation whose ACL is checked. In that case missing a relation is not fine, so this made the code more brittle: a missing relation there would indicate a bug and should error out rather than be skipped silently. Add a missing_ok flag so the silent skip is done only where no lock is held. Callers that hold a lock pass false and still error out on a missing relation. --- src/backend/commands/repack.c | 38 ++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index 02883fe34a4..b09be65da3b 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -172,8 +172,8 @@ static List *get_tables_to_repack(RepackCommand cmd, bool usingindex, static List *get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, bool rel_is_index, MemoryContext permcxt); -static bool repack_is_permitted_for_relation(RepackCommand cmd, - Oid relid, Oid userid); +static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, + Oid userid, bool missing_ok); static void apply_concurrent_changes(BufFile *file, ChangeContext *chgcxt); static void apply_concurrent_insert(Relation rel, TupleTableSlot *slot, @@ -724,7 +724,7 @@ cluster_rel_recheck(RepackCommand cmd, Relation OldHeap, Oid indexOid, Assert(CheckRelationLockedByMe(OldHeap, lmode, false)); /* Check that the user still has privileges for the relation */ - if (!repack_is_permitted_for_relation(cmd, tableOid, userid)) + if (!repack_is_permitted_for_relation(cmd, tableOid, userid, false)) { relation_close(OldHeap, lmode); return false; @@ -2198,7 +2198,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, index->indrelid, - GetUserId())) + GetUserId(), true)) continue; /* Use a permanent memory context for the result list */ @@ -2235,7 +2235,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt) /* noisily skip rels which the user can't process */ if (!repack_is_permitted_for_relation(cmd, class->oid, - GetUserId())) + GetUserId(), true)) continue; /* Use a permanent memory context for the result list */ @@ -2304,7 +2304,7 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, * leaf partition despite having them on the partitioned table. Skip * if so. */ - if (!repack_is_permitted_for_relation(cmd, table_oid, GetUserId())) + if (!repack_is_permitted_for_relation(cmd, table_oid, GetUserId(), true)) continue; /* Use a permanent memory context for the result list */ @@ -2321,16 +2321,21 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid, /* - * Return whether userid has privileges to execute REPACK on relid. + * Check whether the passed-in user has privileges to execute REPACK on the + * relation. * - * Caller may not have a lock on the relation, so it could have been - * dropped concurrently. In that case, silently return false. + * missing_ok should be passed only by callers that hold no lock on the + * relation, where a concurrent drop is possible and fine to skip. A caller + * that holds a lock must not pass it: there a missing relation would indicate + * a bug and should error out rather than be silently skipped. * * If the relation does exist but the user doesn't have the required - * privs, emit a WARNING and return false. Otherwise, return true. + * privileges, emit a WARNING and return false to let the caller + * decide what to do with this relation. */ static bool -repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) +repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid, + bool missing_ok) { bool is_missing = false; AclResult result; @@ -2338,9 +2343,18 @@ repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid) Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK); - result = pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing); + result = pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, + missing_ok ? &is_missing : NULL); + + /* + * If the relation was concurrently dropped, nothing to do. Note that this + * is only reachable when the caller specified missing_ok. + */ if (is_missing) + { + Assert(missing_ok); return false; + } if (result == ACLCHECK_OK) return true; -- 2.47.3 ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-10 17:34 Bharath Rupireddy <[email protected]> parent: Bharath Rupireddy <[email protected]> 0 siblings, 1 reply; 108+ messages in thread From: Bharath Rupireddy @ 2026-07-10 17:34 UTC (permalink / raw) To: Álvaro Herrera <[email protected]>; +Cc: cca5507 <[email protected]>; pgsql-hackers <[email protected]> Hi, On Fri, Jul 10, 2026 at 9:03 AM Bharath Rupireddy <[email protected]> wrote: > > > While looking at it I also realized that get_tables_to_repack_partitioned > > is likewise not careful enough about it: we do IndexGetRelation(, false) > > which fails hard if the pg_index tuple cannot be found, which is the > > wrong thing to do. Agreed. For a single-level partitioned table, dropping a leaf blocks on the parent's AccessExclusiveLock, which REPACK holds, so the leaf can't go away mid-build. But for a multi-level table, REPACK holds a lock only on the top parent, so a lower-level leaf whose immediate parent is an intermediate table isn't protected and can be dropped concurrently. So IndexGetRelation(, false) failing hard there is indeed the wrong thing. > > At the same time, it's annoying that half of the code that clearly > > belongs in that routine is actually in ExecRepack(). I moved that to > > where it rightfully belongs. +1, that's a good cleanup. That code clearly belongs in get_tables_to_repack_partitioned(). >> (The only somewhat annoying thing is that > > we have to NULL-out the Relation pointer after returning; but that's not > > *too* bad IMO.) That's fine. We already NULL out rel after get_tables_to_repack_partitioned() today, so the patch isn't adding anything new there. Relying on a non-NULL return from process_single_relation() to mean partitioned table is a little indirect on first read, but the comments explains it well, and I wouldn't complicate the code to avoid it. > > Any opinions on this? > > I will take a closer look at this in a bit. Patch looks good to me. One nit: + table_oid = IndexGetRelation(child_oid, true); + if (!OidIsValid(table_oid)) + continue; How about a short comment on why this is needed even with a lock on the parent, since that lock doesn't cover lower-level leaves in a multi-level partition tree? -- Bharath Rupireddy Amazon Web Services: https://aws.amazon.com ^ permalink raw reply [nested|flat] 108+ messages in thread
* Re: Do not lock tables in get_tables_to_repack @ 2026-07-11 14:50 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> parent: Bharath Rupireddy <[email protected]> 0 siblings, 0 replies; 108+ messages in thread From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-07-11 14:50 UTC (permalink / raw) To: =?utf-8?B?QmhhcmF0aCBSdXBpcmVkZHk=?= <[email protected]>; =?utf-8?B?w4FsdmFybyBIZXJyZXJh?= <[email protected]>; +Cc: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]> > > > Any opinions on this? > > > > I will take a closer look at this in a bit. > > Patch looks good to me. One nit: > > + table_oid = IndexGetRelation(child_oid, true); > + if (!OidIsValid(table_oid)) > + continue; > > How about a short comment on why this is needed even with a lock on > the parent, since that lock doesn't cover lower-level leaves in a > multi-level partition tree? I think it's worth a comment, too. Patch LGTM. -- Regards, ChangAo Chen ^ permalink raw reply [nested|flat] 108+ messages in thread
end of thread, other threads:[~2026-07-11 14:50 UTC | newest] Thread overview: 108+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2025-09-25 12:58 [PATCH v22 1/2] Split vacuumdb to create vacuuming.c/h Álvaro Herrera <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]> 2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 2026-06-27 19:56 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]> 2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]> 2026-07-08 02:36 ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]> 2026-07-10 14:22 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]> 2026-07-10 16:03 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]> 2026-07-10 17:34 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]> 2026-07-11 14:50 ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
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