From aeabbd9b6e336d086941eb89f2b4983b58c5881e Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Thu, 8 Jan 2026 11:29:59 -0600 Subject: [PATCH v1 1/1] pg_dump: fix use of pg_get_sequence_data --- src/backend/access/sequence/sequence.c | 20 ++++++++++++++++++++ src/backend/commands/sequence.c | 14 ++++++++------ src/bin/pg_dump/pg_dump.c | 10 ++++++++++ src/include/access/sequence.h | 1 + 4 files changed, 39 insertions(+), 6 deletions(-) diff --git a/src/backend/access/sequence/sequence.c b/src/backend/access/sequence/sequence.c index 106af1477e9..6f21f49a520 100644 --- a/src/backend/access/sequence/sequence.c +++ b/src/backend/access/sequence/sequence.c @@ -45,6 +45,26 @@ sequence_open(Oid relationId, LOCKMODE lockmode) return r; } +/* ---------------- + * try_sequence_open - open a sequence relation by relation OID + * + * Same as sequence_open, except return NULL instead of failing if the + * relation does not exist. + * ---------------- + */ +Relation +try_sequence_open(Oid relationId, LOCKMODE lockmode) +{ + Relation r; + + r = try_relation_open(relationId, lockmode); + + if (r) + validate_relation_kind(r); + + return r; +} + /* ---------------- * sequence_close - close a sequence * diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c index 904eeada5ab..e3202dfe951 100644 --- a/src/backend/commands/sequence.c +++ b/src/backend/commands/sequence.c @@ -1794,7 +1794,6 @@ pg_get_sequence_data(PG_FUNCTION_ARGS) { #define PG_GET_SEQUENCE_DATA_COLS 3 Oid relid = PG_GETARG_OID(0); - SeqTable elm; Relation seqrel; Datum values[PG_GET_SEQUENCE_DATA_COLS] = {0}; bool isnull[PG_GET_SEQUENCE_DATA_COLS] = {0}; @@ -1811,13 +1810,15 @@ pg_get_sequence_data(PG_FUNCTION_ARGS) LSNOID, -1, 0); resultTupleDesc = BlessTupleDesc(resultTupleDesc); - init_sequence(relid, &elm, &seqrel); + seqrel = try_sequence_open(relid, AccessShareLock); /* - * Return all NULLs for sequences for which we lack privileges, other - * sessions' temporary sequences, and unlogged sequences on standbys. + * Return all NULLs for missing sequences, sequences for which we lack + * privileges, other sessions' temporary sequences, and unlogged sequences + * on standbys. */ - if (pg_class_aclcheck(relid, GetUserId(), ACL_SELECT) == ACLCHECK_OK && + if (seqrel && + pg_class_aclcheck(relid, GetUserId(), ACL_SELECT) == ACLCHECK_OK && !RELATION_IS_OTHER_TEMP(seqrel) && (RelationIsPermanent(seqrel) || !RecoveryInProgress())) { @@ -1838,7 +1839,8 @@ pg_get_sequence_data(PG_FUNCTION_ARGS) else memset(isnull, true, sizeof(isnull)); - sequence_close(seqrel, NoLock); + if (seqrel) + sequence_close(seqrel, AccessShareLock); resultHeapTuple = heap_form_tuple(resultTupleDesc, values, isnull); result = HeapTupleGetDatum(resultHeapTuple); diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index 7df56d8b1b0..573fb0c06a1 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -137,6 +137,7 @@ typedef struct int64 cache; /* cache size */ int64 last_value; /* last value of sequence */ bool is_called; /* whether nextval advances before returning */ + bool null_seqtuple; /* did pg_get_sequence_data return nulls? */ } SequenceItem; typedef enum OidOptions @@ -18959,6 +18960,7 @@ collectSequences(Archive *fout) sequences[i].cycled = (strcmp(PQgetvalue(res, i, 7), "t") == 0); sequences[i].last_value = strtoi64(PQgetvalue(res, i, 8), NULL, 10); sequences[i].is_called = (strcmp(PQgetvalue(res, i, 9), "t") == 0); + sequences[i].null_seqtuple = (PQgetisnull(res, i, 8) || PQgetisnull(res, i, 9)); } PQclear(res); @@ -19230,6 +19232,10 @@ dumpSequenceData(Archive *fout, const TableDataInfo *tdinfo) bool called; PQExpBuffer query = createPQExpBuffer(); + /* needn't bother if not dumping sequence data */ + if (!fout->dopt->dumpData && !fout->dopt->sequence_data) + return; + /* * For versions >= 18, the sequence information is gathered in the sorted * array before any calls to dumpSequenceData(). See collectSequences() @@ -19271,6 +19277,10 @@ dumpSequenceData(Archive *fout, const TableDataInfo *tdinfo) entry = bsearch(&key, sequences, nsequences, sizeof(SequenceItem), SequenceItemCmp); + if (entry->null_seqtuple) + pg_fatal("failed to get data for sequence \"%s\"; user may lack privileges or sequence may have been dropped", + tbinfo->dobj.name); + last = entry->last_value; called = entry->is_called; } diff --git a/src/include/access/sequence.h b/src/include/access/sequence.h index cbe93775b1b..42f199003b4 100644 --- a/src/include/access/sequence.h +++ b/src/include/access/sequence.h @@ -18,6 +18,7 @@ #include "utils/relcache.h" extern Relation sequence_open(Oid relationId, LOCKMODE lockmode); +extern Relation try_sequence_open(Oid relationId, LOCKMODE lockmode); extern void sequence_close(Relation relation, LOCKMODE lockmode); #endif /* ACCESS_SEQUENCE_H */ -- 2.39.5 (Apple Git-154)