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Diffstat (limited to 'src/backend/commands/sequence.c')
-rw-r--r--src/backend/commands/sequence.c76
1 files changed, 53 insertions, 23 deletions
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 7e85b69ab8f..2d820e5cebc 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -101,7 +101,9 @@ static Form_pg_sequence_data read_seq_tuple(Relation rel,
static void init_params(ParseState *pstate, List *options, bool for_identity,
bool isInit,
Form_pg_sequence seqform,
- Form_pg_sequence_data seqdataform, List **owned_by);
+ Form_pg_sequence_data seqdataform,
+ bool *need_seq_rewrite,
+ 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);
@@ -115,6 +117,7 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
{
FormData_pg_sequence seqform;
FormData_pg_sequence_data seqdataform;
+ bool need_seq_rewrite;
List *owned_by;
CreateStmt *stmt = makeNode(CreateStmt);
Oid seqoid;
@@ -153,7 +156,9 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
}
/* Check and set all option values */
- init_params(pstate, seq->options, seq->for_identity, true, &seqform, &seqdataform, &owned_by);
+ init_params(pstate, seq->options, seq->for_identity, true,
+ &seqform, &seqdataform,
+ &need_seq_rewrite, &owned_by);
/*
* Create relation (and fill value[] and null[] for the tuple)
@@ -417,6 +422,7 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
HeapTupleData datatuple;
Form_pg_sequence seqform;
Form_pg_sequence_data newdataform;
+ bool need_seq_rewrite;
List *owned_by;
ObjectAddress address;
Relation rel;
@@ -461,35 +467,41 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
UnlockReleaseBuffer(buf);
/* Check and set new values */
- init_params(pstate, stmt->options, stmt->for_identity, false, seqform,
- newdataform, &owned_by);
+ init_params(pstate, stmt->options, stmt->for_identity, false,
+ seqform, newdataform,
+ &need_seq_rewrite, &owned_by);
/* Clear local cache so that we don't think we have cached numbers */
/* Note that we do not change the currval() state */
elm->cached = elm->last;
- /* check the comment above nextval_internal()'s equivalent call. */
- if (RelationNeedsWAL(seqrel))
- GetTopTransactionId();
+ /* If needed, rewrite the sequence relation itself */
+ if (need_seq_rewrite)
+ {
+ /* check the comment above nextval_internal()'s equivalent call. */
+ if (RelationNeedsWAL(seqrel))
+ GetTopTransactionId();
- /*
- * 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);
+ /*
+ * 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);
- /*
- * Insert the modified tuple into the new storage file.
- */
- fill_seq_with_data(seqrel, newdatatuple);
+ /*
+ * Insert the modified tuple into the new storage file.
+ */
+ fill_seq_with_data(seqrel, newdatatuple);
+ }
/* process OWNED BY if given */
if (owned_by)
process_owned_by(seqrel, owned_by, stmt->for_identity);
+ /* update the pg_sequence tuple (we could skip this in some cases...) */
CatalogTupleUpdate(rel, &seqtuple->t_self, seqtuple);
InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
@@ -1204,19 +1216,28 @@ read_seq_tuple(Relation rel, Buffer *buf, HeapTuple seqdatatuple)
/*
* 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
- * relation itself. Set *changed_seqform to true if seqform was changed
- * (interesting for ALTER SEQUENCE). Also set *owned_by to any OWNED BY
- * option, or to NIL if there is none.
+ * into the pg_sequence catalog, and fields of seqdataform for changes to the
+ * sequence relation itself. Set *need_seq_rewrite to true if we changed any
+ * parameters that require rewriting the sequence's relation (interesting for
+ * ALTER SEQUENCE). Also set *owned_by to any OWNED BY option, or to NIL if
+ * there is none.
*
* If isInit is true, fill any unspecified options with default values;
* otherwise, do not change existing options that aren't explicitly overridden.
+ *
+ * Note: we force a sequence rewrite whenever we change parameters that affect
+ * generation of future sequence values, even if the seqdataform per se is not
+ * changed. This allows ALTER SEQUENCE to behave transactionally. Currently,
+ * the only option that doesn't cause that is OWNED BY. It's *necessary* for
+ * ALTER SEQUENCE OWNED BY to not rewrite the sequence, because that would
+ * break pg_upgrade by causing unwanted changes in the sequence's relfilenode.
*/
static void
init_params(ParseState *pstate, List *options, bool for_identity,
bool isInit,
Form_pg_sequence seqform,
Form_pg_sequence_data seqdataform,
+ bool *need_seq_rewrite,
List **owned_by)
{
DefElem *as_type = NULL;
@@ -1231,6 +1252,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
bool reset_max_value = false;
bool reset_min_value = false;
+ *need_seq_rewrite = false;
*owned_by = NIL;
foreach(option, options)
@@ -1245,6 +1267,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
as_type = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "increment") == 0)
{
@@ -1254,6 +1277,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
increment_by = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "start") == 0)
{
@@ -1263,6 +1287,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
start_value = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "restart") == 0)
{
@@ -1272,6 +1297,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
restart_value = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "maxvalue") == 0)
{
@@ -1281,6 +1307,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
max_value = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "minvalue") == 0)
{
@@ -1290,6 +1317,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
min_value = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "cache") == 0)
{
@@ -1299,6 +1327,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
cache_value = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "cycle") == 0)
{
@@ -1308,6 +1337,7 @@ init_params(ParseState *pstate, List *options, bool for_identity,
errmsg("conflicting or redundant options"),
parser_errposition(pstate, defel->location)));
is_cycled = defel;
+ *need_seq_rewrite = true;
}
else if (strcmp(defel->defname, "owned_by") == 0)
{
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-23 02:47:17 +0000