On 2019-04-26 15:37, Laurenz Albe wrote:
> What do you think of the patch I just posted on this thread to
> remove ownership automatically when the default is dropped, as Michael
> suggested? I think that would make things much more intuitive from
> the user's perspective.
I think that adds more nonstandard behavior on top of an already
confusing and obsolescent feature, so I can't get too excited about it.
A more forward-looking fix would be your other idea of having
getOwnedSequence() only deal with identity sequences (not serial
sequences). See attached patch for a draft.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From b0a9c3402847f846d6d133cb9eced56ea9634a30 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Sat, 27 Apr 2019 14:12:03 +0200
Subject: [PATCH] Untangle some stuff about identity sequences
XXX draft XXX
---
src/backend/catalog/pg_depend.c | 26 +++++++++++++++++++-------
src/backend/commands/tablecmds.c | 2 +-
src/backend/parser/parse_utilcmd.c | 12 +++++-------
src/backend/rewrite/rewriteHandler.c | 2 +-
src/include/catalog/dependency.h | 2 +-
5 files changed, 27 insertions(+), 17 deletions(-)
diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c
index f7caedcc02..63c94cfbe6 100644
--- a/src/backend/catalog/pg_depend.c
+++ b/src/backend/catalog/pg_depend.c
@@ -707,8 +707,8 @@ sequenceIsOwned(Oid seqId, char deptype, Oid *tableId,
int32 *colId)
* Collect a list of OIDs of all sequences owned by the specified relation,
* and column if specified.
*/
-List *
-getOwnedSequences(Oid relid, AttrNumber attnum)
+static List *
+getOwnedSequences_internal(Oid relid, AttrNumber attnum, char deptype)
{
List *result = NIL;
Relation depRel;
@@ -750,7 +750,8 @@ getOwnedSequences(Oid relid, AttrNumber attnum)
(deprec->deptype == DEPENDENCY_AUTO || deprec->deptype
== DEPENDENCY_INTERNAL) &&
get_rel_relkind(deprec->objid) == RELKIND_SEQUENCE)
{
- result = lappend_oid(result, deprec->objid);
+ if (!deptype || deprec->deptype == deptype)
+ result = lappend_oid(result, deprec->objid);
}
}
@@ -761,18 +762,29 @@ getOwnedSequences(Oid relid, AttrNumber attnum)
return result;
}
+List *
+getOwnedSequences(Oid relid, AttrNumber attnum)
+{
+ return getOwnedSequences_internal(relid, attnum, 0);
+}
+
/*
- * Get owned sequence, error if not exactly one.
+ * Get owned identity sequence, error if not exactly one.
*/
Oid
-getOwnedSequence(Oid relid, AttrNumber attnum)
+getIdentitySequence(Oid relid, AttrNumber attnum, bool missing_ok)
{
- List *seqlist = getOwnedSequences(relid, attnum);
+ List *seqlist = getOwnedSequences_internal(relid, attnum,
DEPENDENCY_INTERNAL);
if (list_length(seqlist) > 1)
elog(ERROR, "more than one owned sequence found");
else if (list_length(seqlist) < 1)
- elog(ERROR, "no owned sequence found");
+ {
+ if (missing_ok)
+ return InvalidOid;
+ else
+ elog(ERROR, "no owned sequence found");
+ }
return linitial_oid(seqlist);
}
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 14fcad9034..53dc72f7d6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -6607,7 +6607,7 @@ ATExecDropIdentity(Relation rel, const char *colName,
bool missing_ok, LOCKMODE
table_close(attrelation, RowExclusiveLock);
/* drop the internal sequence */
- seqid = getOwnedSequence(RelationGetRelid(rel), attnum);
+ seqid = getIdentitySequence(RelationGetRelid(rel), attnum, false);
deleteDependencyRecordsForClass(RelationRelationId, seqid,
RelationRelationId, DEPENDENCY_INTERNAL);
CommandCounterIncrement();
diff --git a/src/backend/parser/parse_utilcmd.c
b/src/backend/parser/parse_utilcmd.c
index 4564c0ae81..a3c5b005d5 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -1083,7 +1083,7 @@ transformTableLikeClause(CreateStmtContext *cxt,
TableLikeClause *table_like_cla
* find sequence owned by old column; extract sequence
parameters;
* build new create sequence command
*/
- seq_relid =
getOwnedSequence(RelationGetRelid(relation), attribute->attnum);
+ seq_relid =
getIdentitySequence(RelationGetRelid(relation), attribute->attnum, false);
seq_options = sequence_options(seq_relid);
generateSerialExtraStmts(cxt, def,
InvalidOid, seq_options, true,
@@ -3165,7 +3165,7 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
if (attnum != InvalidAttrNumber &&
TupleDescAttr(tupdesc, attnum -
1)->attidentity)
{
- Oid
seq_relid = getOwnedSequence(relid, attnum);
+ Oid
seq_relid = getIdentitySequence(relid, attnum, false);
Oid typeOid
= typenameTypeId(pstate, def->typeName);
AlterSeqStmt *altseqstmt =
makeNode(AlterSeqStmt);
@@ -3216,7 +3216,6 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
ListCell *lc;
List *newseqopts = NIL;
List *newdef = NIL;
- List *seqlist;
AttrNumber attnum;
/*
@@ -3237,14 +3236,13 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
if (attnum)
{
- seqlist =
getOwnedSequences(relid, attnum);
- if (seqlist)
+ Oid
seq_relid = getIdentitySequence(relid, attnum, true);
+
+ if (seq_relid)
{
AlterSeqStmt *seqstmt;
- Oid
seq_relid;
seqstmt =
makeNode(AlterSeqStmt);
- seq_relid =
linitial_oid(seqlist);
seqstmt->sequence =
makeRangeVar(get_namespace_name(get_rel_namespace(seq_relid)),
get_rel_name(seq_relid), -1);
seqstmt->options =
newseqopts;
diff --git a/src/backend/rewrite/rewriteHandler.c
b/src/backend/rewrite/rewriteHandler.c
index 39080776b0..fce361fc6a 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -1130,7 +1130,7 @@ build_column_default(Relation rel, int attrno)
{
NextValueExpr *nve = makeNode(NextValueExpr);
- nve->seqid = getOwnedSequence(RelationGetRelid(rel), attrno);
+ nve->seqid = getIdentitySequence(RelationGetRelid(rel), attrno,
false);
nve->typeId = att_tup->atttypid;
return (Node *) nve;
diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h
index 57545b70d8..495a591934 100644
--- a/src/include/catalog/dependency.h
+++ b/src/include/catalog/dependency.h
@@ -209,7 +209,7 @@ extern Oid getExtensionOfObject(Oid classId, Oid objectId);
extern bool sequenceIsOwned(Oid seqId, char deptype, Oid *tableId, int32
*colId);
extern List *getOwnedSequences(Oid relid, AttrNumber attnum);
-extern Oid getOwnedSequence(Oid relid, AttrNumber attnum);
+extern Oid getIdentitySequence(Oid relid, AttrNumber attnum, bool
missing_ok);
extern Oid get_constraint_index(Oid constraintId);
--
2.21.0
