Change nextval and other sequence functions to specify their sequence

argument as a 'regclass' value instead of a text string.  The frontend
conversion of text string to pg_class OID is now encapsulated as an
implicitly-invocable coercion from text to regclass.  This provides
backwards compatibility to the old behavior when the sequence argument
is explicitly typed as 'text'.  When the argument is just an unadorned
literal string, it will be taken as 'regclass', which means that the
stored representation will be an OID.  This solves longstanding problems
with renaming sequences that are referenced in default expressions, as
well as new-in-8.1 problems with renaming such sequences' schemas or
moving them to another schema.  All per recent discussion.
Along the way, fix some rather serious problems in dbmirror's support
for mirroring sequence operations (int4 vs int8 confusion for instance).

1 files changed, 59 insertions, 43 deletions

diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 5af9ba55b6e..9bf801f2308 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.123 2005/06/07 07:08:34 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.124 2005/10/02 23:50:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -75,12 +75,12 @@ static SeqTable seqtab = NULL;	/* Head of list of SeqTable items */
  */
 static SeqTableData *last_used_seq = NULL;
 
+static int64 nextval_internal(Oid relid);
 static void acquire_share_lock(Relation seqrel, SeqTable seq);
-static void init_sequence(RangeVar *relation,
-			  SeqTable *p_elm, Relation *p_rel);
+static void init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel);
 static Form_pg_sequence read_info(SeqTable elm, Relation rel, Buffer *buf);
 static void init_params(List *options, Form_pg_sequence new, bool isInit);
-static void do_setval(RangeVar *sequence, int64 next, bool iscalled);
+static void do_setval(Oid relid, int64 next, bool iscalled);
 
 /*
  * DefineSequence
@@ -302,6 +302,7 @@ DefineSequence(CreateSeqStmt *seq)
 void
 AlterSequence(AlterSeqStmt *stmt)
 {
+	Oid			relid;
 	SeqTable	elm;
 	Relation	seqrel;
 	Buffer		buf;
@@ -310,7 +311,8 @@ AlterSequence(AlterSeqStmt *stmt)
 	FormData_pg_sequence new;
 
 	/* open and AccessShareLock sequence */
-	init_sequence(stmt->sequence, &elm, &seqrel);
+	relid = RangeVarGetRelid(stmt->sequence, false);
+	init_sequence(relid, &elm, &seqrel);
 
 	/* allow ALTER to sequence owner only */
 	if (!pg_class_ownercheck(elm->relid, GetUserId()))
@@ -372,11 +374,35 @@ AlterSequence(AlterSeqStmt *stmt)
 }
 
 
+/*
+ * Note: nextval with a text argument is no longer exported as a pg_proc
+ * entry, but we keep it around to ease porting of C code that may have
+ * called the function directly.
+ */
 Datum
 nextval(PG_FUNCTION_ARGS)
 {
 	text	   *seqin = PG_GETARG_TEXT_P(0);
 	RangeVar   *sequence;
+	Oid			relid;
+
+	sequence = makeRangeVarFromNameList(textToQualifiedNameList(seqin));
+	relid = RangeVarGetRelid(sequence, false);
+
+	PG_RETURN_INT64(nextval_internal(relid));
+}
+
+Datum
+nextval_oid(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+
+	PG_RETURN_INT64(nextval_internal(relid));
+}
+
+static int64
+nextval_internal(Oid relid)
+{
 	SeqTable	elm;
 	Relation	seqrel;
 	Buffer		buf;
@@ -394,23 +420,21 @@ nextval(PG_FUNCTION_ARGS)
 				rescnt = 0;
 	bool		logit = false;
 
-	sequence = makeRangeVarFromNameList(textToQualifiedNameList(seqin));
-
 	/* open and AccessShareLock sequence */
-	init_sequence(sequence, &elm, &seqrel);
+	init_sequence(relid, &elm, &seqrel);
 
 	if (pg_class_aclcheck(elm->relid, GetUserId(), ACL_UPDATE) != ACLCHECK_OK)
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("permission denied for sequence %s",
-						sequence->relname)));
+						RelationGetRelationName(seqrel))));
 
 	if (elm->last != elm->cached)		/* some numbers were cached */
 	{
 		last_used_seq = elm;
 		elm->last += elm->increment;
 		relation_close(seqrel, NoLock);
-		PG_RETURN_INT64(elm->last);
+		return elm->last;
 	}
 
 	/* lock page' buffer and read tuple */
@@ -481,7 +505,7 @@ nextval(PG_FUNCTION_ARGS)
 					ereport(ERROR,
 					  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 					   errmsg("nextval: reached maximum value of sequence \"%s\" (%s)",
-							  sequence->relname, buf)));
+							  RelationGetRelationName(seqrel), buf)));
 				}
 				next = minv;
 			}
@@ -504,7 +528,7 @@ nextval(PG_FUNCTION_ARGS)
 					ereport(ERROR,
 					  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 					   errmsg("nextval: reached minimum value of sequence \"%s\" (%s)",
-							  sequence->relname, buf)));
+							  RelationGetRelationName(seqrel), buf)));
 				}
 				next = maxv;
 			}
@@ -576,34 +600,31 @@ nextval(PG_FUNCTION_ARGS)
 
 	relation_close(seqrel, NoLock);
 
-	PG_RETURN_INT64(result);
+	return result;
 }
 
 Datum
-currval(PG_FUNCTION_ARGS)
+currval_oid(PG_FUNCTION_ARGS)
 {
-	text	   *seqin = PG_GETARG_TEXT_P(0);
-	RangeVar   *sequence;
+	Oid			relid = PG_GETARG_OID(0);
+	int64		result;
 	SeqTable	elm;
 	Relation	seqrel;
-	int64		result;
-
-	sequence = makeRangeVarFromNameList(textToQualifiedNameList(seqin));
 
 	/* open and AccessShareLock sequence */
-	init_sequence(sequence, &elm, &seqrel);
+	init_sequence(relid, &elm, &seqrel);
 
 	if (pg_class_aclcheck(elm->relid, GetUserId(), ACL_SELECT) != ACLCHECK_OK)
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("permission denied for sequence %s",
-						sequence->relname)));
+						RelationGetRelationName(seqrel))));
 
 	if (elm->increment == 0)	/* nextval/read_info were not called */
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("currval of sequence \"%s\" is not yet defined in this session",
-						sequence->relname)));
+						RelationGetRelationName(seqrel))));
 
 	result = elm->last;
 
@@ -645,6 +666,7 @@ lastval(PG_FUNCTION_ARGS)
 
 	result = last_used_seq->last;
 	relation_close(seqrel, NoLock);
+
 	PG_RETURN_INT64(result);
 }
 
@@ -662,7 +684,7 @@ lastval(PG_FUNCTION_ARGS)
  * sequence.
  */
 static void
-do_setval(RangeVar *sequence, int64 next, bool iscalled)
+do_setval(Oid relid, int64 next, bool iscalled)
 {
 	SeqTable	elm;
 	Relation	seqrel;
@@ -670,13 +692,13 @@ do_setval(RangeVar *sequence, int64 next, bool iscalled)
 	Form_pg_sequence seq;
 
 	/* open and AccessShareLock sequence */
-	init_sequence(sequence, &elm, &seqrel);
+	init_sequence(relid, &elm, &seqrel);
 
 	if (pg_class_aclcheck(elm->relid, GetUserId(), ACL_UPDATE) != ACLCHECK_OK)
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("permission denied for sequence %s",
-						sequence->relname)));
+						RelationGetRelationName(seqrel))));
 
 	/* lock page' buffer and read tuple */
 	seq = read_info(elm, seqrel, &buf);
@@ -693,7 +715,8 @@ do_setval(RangeVar *sequence, int64 next, bool iscalled)
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("setval: value %s is out of bounds for sequence \"%s\" (%s..%s)",
-						bufv, sequence->relname, bufm, bufx)));
+						bufv, RelationGetRelationName(seqrel),
+						bufm, bufx)));
 	}
 
 	/* save info in local cache */
@@ -753,15 +776,12 @@ do_setval(RangeVar *sequence, int64 next, bool iscalled)
  * See do_setval for discussion.
  */
 Datum
-setval(PG_FUNCTION_ARGS)
+setval_oid(PG_FUNCTION_ARGS)
 {
-	text	   *seqin = PG_GETARG_TEXT_P(0);
+	Oid			relid = PG_GETARG_OID(0);
 	int64		next = PG_GETARG_INT64(1);
-	RangeVar   *sequence;
 
-	sequence = makeRangeVarFromNameList(textToQualifiedNameList(seqin));
-
-	do_setval(sequence, next, true);
+	do_setval(relid, next, true);
 
 	PG_RETURN_INT64(next);
 }
@@ -771,16 +791,13 @@ setval(PG_FUNCTION_ARGS)
  * See do_setval for discussion.
  */
 Datum
-setval_and_iscalled(PG_FUNCTION_ARGS)
+setval3_oid(PG_FUNCTION_ARGS)
 {
-	text	   *seqin = PG_GETARG_TEXT_P(0);
+	Oid			relid = PG_GETARG_OID(0);
 	int64		next = PG_GETARG_INT64(1);
 	bool		iscalled = PG_GETARG_BOOL(2);
-	RangeVar   *sequence;
 
-	sequence = makeRangeVarFromNameList(textToQualifiedNameList(seqin));
-
-	do_setval(sequence, next, iscalled);
+	do_setval(relid, next, iscalled);
 
 	PG_RETURN_INT64(next);
 }
@@ -822,15 +839,14 @@ acquire_share_lock(Relation seqrel, SeqTable seq)
 }
 
 /*
- * Given a relation name, open and lock the sequence.  p_elm and p_rel are
+ * Given a relation OID, open and lock the sequence.  p_elm and p_rel are
  * output parameters.
  */
 static void
-init_sequence(RangeVar *relation, SeqTable *p_elm, Relation *p_rel)
+init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel)
 {
-	Oid			relid = RangeVarGetRelid(relation, false);
-	volatile SeqTable elm;
 	Relation	seqrel;
+	volatile SeqTable elm;
 
 	/*
 	 * Open the sequence relation.
@@ -841,7 +857,7 @@ init_sequence(RangeVar *relation, SeqTable *p_elm, Relation *p_rel)
 		ereport(ERROR,
 				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 				 errmsg("\"%s\" is not a sequence",
-						relation->relname)));
+						RelationGetRelationName(seqrel))));
 
 	/* Look to see if we already have a seqtable entry for relation */
 	for (elm = seqtab; elm != NULL; elm = elm->next)