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-rw-r--r--src/backend/commands/sequence.c123
-rw-r--r--src/test/isolation/expected/sequence-ddl.out30
-rw-r--r--src/test/isolation/specs/sequence-ddl.spec19
3 files changed, 58 insertions, 114 deletions
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 568b3022f2d..4a56f03e8b6 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -98,11 +98,9 @@ static void create_seq_hashtable(void);
static void init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel);
static Form_pg_sequence_data read_seq_tuple(Relation rel,
Buffer *buf, HeapTuple seqdatatuple);
-static LOCKMODE alter_sequence_get_lock_level(List *options);
static void init_params(ParseState *pstate, List *options, bool for_identity,
bool isInit,
Form_pg_sequence seqform,
- bool *changed_seqform,
Form_pg_sequence_data seqdataform, List **owned_by);
static void do_setval(Oid relid, int64 next, bool iscalled);
static void process_owned_by(Relation seqrel, List *owned_by, bool for_identity);
@@ -117,7 +115,6 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
{
FormData_pg_sequence seqform;
FormData_pg_sequence_data seqdataform;
- bool changed_seqform = false; /* not used here */
List *owned_by;
CreateStmt *stmt = makeNode(CreateStmt);
Oid seqoid;
@@ -156,7 +153,7 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
}
/* Check and set all option values */
- init_params(pstate, seq->options, seq->for_identity, true, &seqform, &changed_seqform, &seqdataform, &owned_by);
+ init_params(pstate, seq->options, seq->for_identity, true, &seqform, &seqdataform, &owned_by);
/*
* Create relation (and fill value[] and null[] for the tuple)
@@ -417,19 +414,18 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
SeqTable elm;
Relation seqrel;
Buffer buf;
- HeapTupleData seqdatatuple;
+ HeapTupleData datatuple;
Form_pg_sequence seqform;
- Form_pg_sequence_data seqdata;
- FormData_pg_sequence_data newseqdata;
- bool changed_seqform = false;
+ Form_pg_sequence_data newdataform;
List *owned_by;
ObjectAddress address;
Relation rel;
- HeapTuple tuple;
+ HeapTuple seqtuple;
+ HeapTuple newdatatuple;
/* Open and lock sequence. */
relid = RangeVarGetRelid(stmt->sequence,
- alter_sequence_get_lock_level(stmt->options),
+ ShareRowExclusiveLock,
stmt->missing_ok);
if (relid == InvalidOid)
{
@@ -447,22 +443,26 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
stmt->sequence->relname);
rel = heap_open(SequenceRelationId, RowExclusiveLock);
- tuple = SearchSysCacheCopy1(SEQRELID,
- ObjectIdGetDatum(relid));
- if (!HeapTupleIsValid(tuple))
+ seqtuple = SearchSysCacheCopy1(SEQRELID,
+ ObjectIdGetDatum(relid));
+ if (!HeapTupleIsValid(seqtuple))
elog(ERROR, "cache lookup failed for sequence %u",
relid);
- seqform = (Form_pg_sequence) GETSTRUCT(tuple);
+ seqform = (Form_pg_sequence) GETSTRUCT(seqtuple);
/* lock page's buffer and read tuple into new sequence structure */
- seqdata = read_seq_tuple(seqrel, &buf, &seqdatatuple);
+ (void) read_seq_tuple(seqrel, &buf, &datatuple);
- /* Copy old sequence data into workspace */
- memcpy(&newseqdata, seqdata, sizeof(FormData_pg_sequence_data));
+ /* copy the existing sequence data tuple, so it can be modified localy */
+ newdatatuple = heap_copytuple(&datatuple);
+ newdataform = (Form_pg_sequence_data) GETSTRUCT(newdatatuple);
+
+ UnlockReleaseBuffer(buf);
/* Check and set new values */
- init_params(pstate, stmt->options, stmt->for_identity, false, seqform, &changed_seqform, &newseqdata, &owned_by);
+ init_params(pstate, stmt->options, stmt->for_identity, false, seqform,
+ newdataform, &owned_by);
/* Clear local cache so that we don't think we have cached numbers */
/* Note that we do not change the currval() state */
@@ -472,36 +472,19 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
if (RelationNeedsWAL(seqrel))
GetTopTransactionId();
- /* Now okay to update the on-disk tuple */
- START_CRIT_SECTION();
-
- memcpy(seqdata, &newseqdata, sizeof(FormData_pg_sequence_data));
-
- MarkBufferDirty(buf);
-
- /* XLOG stuff */
- if (RelationNeedsWAL(seqrel))
- {
- xl_seq_rec xlrec;
- XLogRecPtr recptr;
- Page page = BufferGetPage(buf);
-
- XLogBeginInsert();
- XLogRegisterBuffer(0, buf, REGBUF_WILL_INIT);
-
- xlrec.node = seqrel->rd_node;
- XLogRegisterData((char *) &xlrec, sizeof(xl_seq_rec));
-
- XLogRegisterData((char *) seqdatatuple.t_data, seqdatatuple.t_len);
-
- recptr = XLogInsert(RM_SEQ_ID, XLOG_SEQ_LOG);
-
- PageSetLSN(page, recptr);
- }
-
- END_CRIT_SECTION();
+ /*
+ * Create a new storage file for the sequence, making the state changes
+ * transactional. We want to keep the sequence's relfrozenxid at 0, since
+ * it won't contain any unfrozen XIDs. Same with relminmxid, since a
+ * sequence will never contain multixacts.
+ */
+ RelationSetNewRelfilenode(seqrel, seqrel->rd_rel->relpersistence,
+ InvalidTransactionId, InvalidMultiXactId);
- UnlockReleaseBuffer(buf);
+ /*
+ * Insert the modified tuple into the new storage file.
+ */
+ fill_seq_with_data(seqrel, newdatatuple);
/* process OWNED BY if given */
if (owned_by)
@@ -511,10 +494,9 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
ObjectAddressSet(address, RelationRelationId, relid);
- if (changed_seqform)
- CatalogTupleUpdate(rel, &tuple->t_self, tuple);
- heap_close(rel, RowExclusiveLock);
+ CatalogTupleUpdate(rel, &seqtuple->t_self, seqtuple);
+ heap_close(rel, RowExclusiveLock);
relation_close(seqrel, NoLock);
return address;
@@ -1220,30 +1202,6 @@ read_seq_tuple(Relation rel, Buffer *buf, HeapTuple seqdatatuple)
}
/*
- * Check the sequence options list and return the appropriate lock level for
- * ALTER SEQUENCE.
- *
- * Most sequence option changes require a self-exclusive lock and should block
- * concurrent nextval() et al. But RESTART does not, because it's not
- * transactional. Also take a lower lock if no option at all is present.
- */
-static LOCKMODE
-alter_sequence_get_lock_level(List *options)
-{
- ListCell *option;
-
- foreach(option, options)
- {
- DefElem *defel = (DefElem *) lfirst(option);
-
- if (strcmp(defel->defname, "restart") != 0)
- return ShareRowExclusiveLock;
- }
-
- return RowExclusiveLock;
-}
-
-/*
* init_params: process the options list of CREATE or ALTER SEQUENCE, and
* store the values into appropriate fields of seqform, for changes that go
* into the pg_sequence catalog, and seqdataform for changes to the sequence
@@ -1258,7 +1216,6 @@ static void
init_params(ParseState *pstate, List *options, bool for_identity,
bool isInit,
Form_pg_sequence seqform,
- bool *changed_seqform,
Form_pg_sequence_data seqdataform,
List **owned_by)
{
@@ -1378,8 +1335,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
defel->defname);
}
- *changed_seqform = false;
-
/*
* We must reset log_cnt when isInit or when changing any parameters that
* would affect future nextval allocations.
@@ -1420,19 +1375,16 @@ init_params(ParseState *pstate, List *options, bool for_identity,
}
seqform->seqtypid = newtypid;
- *changed_seqform = true;
}
else if (isInit)
{
seqform->seqtypid = INT8OID;
- *changed_seqform = true;
}
/* INCREMENT BY */
if (increment_by != NULL)
{
seqform->seqincrement = defGetInt64(increment_by);
- *changed_seqform = true;
if (seqform->seqincrement == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -1442,28 +1394,24 @@ init_params(ParseState *pstate, List *options, bool for_identity,
else if (isInit)
{
seqform->seqincrement = 1;
- *changed_seqform = true;
}
/* CYCLE */
if (is_cycled != NULL)
{
seqform->seqcycle = intVal(is_cycled->arg);
- *changed_seqform = true;
Assert(BoolIsValid(seqform->seqcycle));
seqdataform->log_cnt = 0;
}
else if (isInit)
{
seqform->seqcycle = false;
- *changed_seqform = true;
}
/* MAXVALUE (null arg means NO MAXVALUE) */
if (max_value != NULL && max_value->arg)
{
seqform->seqmax = defGetInt64(max_value);
- *changed_seqform = true;
seqdataform->log_cnt = 0;
}
else if (isInit || max_value != NULL || reset_max_value)
@@ -1480,7 +1428,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
}
else
seqform->seqmax = -1; /* descending seq */
- *changed_seqform = true;
seqdataform->log_cnt = 0;
}
@@ -1502,7 +1449,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
if (min_value != NULL && min_value->arg)
{
seqform->seqmin = defGetInt64(min_value);
- *changed_seqform = true;
seqdataform->log_cnt = 0;
}
else if (isInit || min_value != NULL || reset_min_value)
@@ -1519,7 +1465,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
}
else
seqform->seqmin = 1; /* ascending seq */
- *changed_seqform = true;
seqdataform->log_cnt = 0;
}
@@ -1555,7 +1500,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
if (start_value != NULL)
{
seqform->seqstart = defGetInt64(start_value);
- *changed_seqform = true;
}
else if (isInit)
{
@@ -1563,7 +1507,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
seqform->seqstart = seqform->seqmin; /* ascending seq */
else
seqform->seqstart = seqform->seqmax; /* descending seq */
- *changed_seqform = true;
}
/* crosscheck START */
@@ -1638,7 +1581,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
if (cache_value != NULL)
{
seqform->seqcache = defGetInt64(cache_value);
- *changed_seqform = true;
if (seqform->seqcache <= 0)
{
char buf[100];
@@ -1654,7 +1596,6 @@ init_params(ParseState *pstate, List *options, bool for_identity,
else if (isInit)
{
seqform->seqcache = 1;
- *changed_seqform = true;
}
}
diff --git a/src/test/isolation/expected/sequence-ddl.out b/src/test/isolation/expected/sequence-ddl.out
index 6b7119738ff..6766c0aff61 100644
--- a/src/test/isolation/expected/sequence-ddl.out
+++ b/src/test/isolation/expected/sequence-ddl.out
@@ -13,15 +13,13 @@ step s1commit: COMMIT;
step s2nv: <... completed>
error in steps s1commit s2nv: ERROR: nextval: reached maximum value of sequence "seq1" (10)
-starting permutation: s2begin s2nv s1alter2 s2commit s1commit
-step s2begin: BEGIN;
-step s2nv: SELECT nextval('seq1') FROM generate_series(1, 15);
+starting permutation: s1restart s2nv s1commit
+step s1restart: ALTER SEQUENCE seq1 RESTART WITH 5;
+step s2nv: SELECT nextval('seq1') FROM generate_series(1, 15); <waiting ...>
+step s1commit: COMMIT;
+step s2nv: <... completed>
nextval
-1
-2
-3
-4
5
6
7
@@ -33,14 +31,16 @@ nextval
13
14
15
-step s1alter2: ALTER SEQUENCE seq1 MAXVALUE 20; <waiting ...>
-step s2commit: COMMIT;
-step s1alter2: <... completed>
-step s1commit: COMMIT;
+16
+17
+18
+19
starting permutation: s1restart s2nv s1commit
step s1restart: ALTER SEQUENCE seq1 RESTART WITH 5;
-step s2nv: SELECT nextval('seq1') FROM generate_series(1, 15);
+step s2nv: SELECT nextval('seq1') FROM generate_series(1, 15); <waiting ...>
+step s1commit: COMMIT;
+step s2nv: <... completed>
nextval
5
@@ -58,9 +58,8 @@ nextval
17
18
19
-step s1commit: COMMIT;
-starting permutation: s2begin s2nv s1restart s2commit s1commit
+starting permutation: s2begin s2nv s1alter2 s2commit s1commit
step s2begin: BEGIN;
step s2nv: SELECT nextval('seq1') FROM generate_series(1, 15);
nextval
@@ -80,6 +79,7 @@ nextval
13
14
15
-step s1restart: ALTER SEQUENCE seq1 RESTART WITH 5;
+step s1alter2: ALTER SEQUENCE seq1 MAXVALUE 20; <waiting ...>
step s2commit: COMMIT;
+step s1alter2: <... completed>
step s1commit: COMMIT;
diff --git a/src/test/isolation/specs/sequence-ddl.spec b/src/test/isolation/specs/sequence-ddl.spec
index 42ee3b06151..5c51fcdae68 100644
--- a/src/test/isolation/specs/sequence-ddl.spec
+++ b/src/test/isolation/specs/sequence-ddl.spec
@@ -15,6 +15,7 @@ setup { BEGIN; }
step "s1alter" { ALTER SEQUENCE seq1 MAXVALUE 10; }
step "s1alter2" { ALTER SEQUENCE seq1 MAXVALUE 20; }
step "s1restart" { ALTER SEQUENCE seq1 RESTART WITH 5; }
+step "s1setval" { SELECT setval('seq1', 5); }
step "s1commit" { COMMIT; }
session "s2"
@@ -24,16 +25,18 @@ step "s2commit" { COMMIT; }
permutation "s1alter" "s1commit" "s2nv"
-# Prior to PG10, the s2nv would see the uncommitted s1alter change,
-# but now it waits.
+# Prior to PG10, the s2nv step would see the uncommitted s1alter
+# change, but now it waits.
permutation "s1alter" "s2nv" "s1commit"
-# nextval doesn't release lock until transaction end, so s1alter2 has
-# to wait for s2commit.
-permutation "s2begin" "s2nv" "s1alter2" "s2commit" "s1commit"
+# Prior to PG10, the s2nv step would see the uncommitted s1reset
+# change, but now it waits.
+permutation "s1restart" "s2nv" "s1commit"
-# RESTART is nontransactional, so s2nv sees it right away
+# In contrast to ALTER setval() is non-transactional, so it doesn't
+# have to wait.
permutation "s1restart" "s2nv" "s1commit"
-# RESTART does not wait
-permutation "s2begin" "s2nv" "s1restart" "s2commit" "s1commit"
+# nextval doesn't release lock until transaction end, so s1alter2 has
+# to wait for s2commit.
+permutation "s2begin" "s2nv" "s1alter2" "s2commit" "s1commit"
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-22 18:20:33 +0000