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Fix ALTER SEQUENCE OWNED BY to not rewrite the sequence relation.

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It's not necessary for it to do that, since OWNED BY requires only ordinary
catalog updates and doesn't affect future sequence values.  And pg_upgrade
needs to use OWNED BY without having it change the sequence's relfilenode.
Commit 3d79013b9 broke this by making all forms of ALTER SEQUENCE change
the relfilenode; that seems to be the explanation for the hard-to-reproduce
buildfarm failures we've been seeing since then.

Discussion: https://postgr.es/m/19785.1497215827@sss.pgh.pa.us
pull/23/head
Tom Lane 8 years ago
parent 5d8beac8be
commit a475e46634
1 changed files with 53 additions and 23 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 76
      src/backend/commands/sequence.c

76
src/backend/commands/sequence.c
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@ -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)
{

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