Change many routines to return ObjectAddress rather than OID

The changed routines are mostly those that can be directly called by
ProcessUtilitySlow; the intention is to make the affected object
information more precise, in support for future event trigger changes.
Originally it was envisioned that the OID of the affected object would
be enough, and in most cases that is correct, but upon actually
implementing the event trigger changes it turned out that ObjectAddress
is more widely useful.

Additionally, some command execution routines grew an output argument
that's an object address which provides further info about the executed
command.  To wit:

* for ALTER DOMAIN / ADD CONSTRAINT, it corresponds to the address of
  the new constraint

* for ALTER OBJECT / SET SCHEMA, it corresponds to the address of the
  schema that originally contained the object.

* for ALTER EXTENSION {ADD, DROP} OBJECT, it corresponds to the address
  of the object added to or dropped from the extension.

There's no user-visible change in this commit, and no functional change
either.

Discussion: 20150218213255.GC6717@tamriel.snowman.net
Reviewed-By: Stephen Frost, Andres Freund

1 files changed, 65 insertions, 38 deletions

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 745502072e6..653677892de 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -435,17 +435,19 @@ static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid,
  * The other arguments are used to extend the behavior for other cases:
  * relkind: relkind to assign to the new relation
  * ownerId: if not InvalidOid, use this as the new relation's owner.
+ * typaddress: if not null, it's set to the pg_type entry's address.
  *
  * Note that permissions checks are done against current user regardless of
  * ownerId.  A nonzero ownerId is used when someone is creating a relation
  * "on behalf of" someone else, so we still want to see that the current user
  * has permissions to do it.
  *
- * If successful, returns the OID of the new relation.
+ * If successful, returns the address of the new relation.
  * ----------------------------------------------------------------
  */
-Oid
-DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId)
+ObjectAddress
+DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
+			   ObjectAddress *typaddress)
 {
 	char		relname[NAMEDATALEN];
 	Oid			namespaceId;
@@ -465,6 +467,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId)
 	AttrNumber	attnum;
 	static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
 	Oid			ofTypeId;
+	ObjectAddress address;
 
 	/*
 	 * Truncate relname to appropriate length (probably a waste of time, as
@@ -657,7 +660,8 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId)
 										  reloptions,
 										  true,
 										  allowSystemTableMods,
-										  false);
+										  false,
+										  typaddress);
 
 	/* Store inheritance information for new rel. */
 	StoreCatalogInheritance(relationId, inheritOids);
@@ -689,13 +693,15 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId)
 		AddRelationNewConstraints(rel, rawDefaults, stmt->constraints,
 								  true, true, false);
 
+	ObjectAddressSet(address, RelationRelationId, relationId);
+
 	/*
 	 * Clean up.  We keep lock on new relation (although it shouldn't be
 	 * visible to anyone else anyway, until commit).
 	 */
 	relation_close(rel, NoLock);
 
-	return relationId;
+	return address;
 }
 
 /*
@@ -2158,8 +2164,10 @@ renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing)
 
 /*
  *		renameatt_internal		- workhorse for renameatt
+ *
+ * Return value is the attribute number in the 'myrelid' relation.
  */
-static void
+static AttrNumber
 renameatt_internal(Oid myrelid,
 				   const char *oldattname,
 				   const char *newattname,
@@ -2172,7 +2180,7 @@ renameatt_internal(Oid myrelid,
 	Relation	attrelation;
 	HeapTuple	atttup;
 	Form_pg_attribute attform;
-	int			attnum;
+	AttrNumber	attnum;
 
 	/*
 	 * Grab an exclusive lock on the target table, which we will NOT release
@@ -2300,6 +2308,8 @@ renameatt_internal(Oid myrelid,
 	heap_close(attrelation, RowExclusiveLock);
 
 	relation_close(targetrelation, NoLock);		/* close rel but keep lock */
+
+	return attnum;
 }
 
 /*
@@ -2322,11 +2332,15 @@ RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid,
 
 /*
  *		renameatt		- changes the name of a attribute in a relation
+ *
+ * The returned ObjectAddress is that of the renamed column.
  */
-Oid
+ObjectAddress
 renameatt(RenameStmt *stmt)
 {
 	Oid			relid;
+	AttrNumber	attnum;
+	ObjectAddress address;
 
 	/* lock level taken here should match renameatt_internal */
 	relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
@@ -2339,26 +2353,27 @@ renameatt(RenameStmt *stmt)
 		ereport(NOTICE,
 				(errmsg("relation \"%s\" does not exist, skipping",
 						stmt->relation->relname)));
-		return InvalidOid;
+		return InvalidObjectAddress;
 	}
 
-	renameatt_internal(relid,
-					   stmt->subname,	/* old att name */
-					   stmt->newname,	/* new att name */
-					   interpretInhOption(stmt->relation->inhOpt),		/* recursive? */
-					   false,	/* recursing? */
-					   0,		/* expected inhcount */
-					   stmt->behavior);
+	attnum =
+		renameatt_internal(relid,
+						   stmt->subname,		/* old att name */
+						   stmt->newname,		/* new att name */
+						   interpretInhOption(stmt->relation->inhOpt),	/* recursive? */
+						   false,		/* recursing? */
+						   0,	/* expected inhcount */
+						   stmt->behavior);
 
-	/* This is an ALTER TABLE command so it's about the relid */
-	return relid;
-}
+	ObjectAddressSubSet(address, RelationRelationId, relid, attnum);
 
+	return address;
+}
 
 /*
  * same logic as renameatt_internal
  */
-static Oid
+static ObjectAddress
 rename_constraint_internal(Oid myrelid,
 						   Oid mytypid,
 						   const char *oldconname,
@@ -2371,6 +2386,7 @@ rename_constraint_internal(Oid myrelid,
 	Oid			constraintOid;
 	HeapTuple	tuple;
 	Form_pg_constraint con;
+	ObjectAddress address;
 
 	AssertArg(!myrelid || !mytypid);
 
@@ -2446,15 +2462,17 @@ rename_constraint_internal(Oid myrelid,
 	else
 		RenameConstraintById(constraintOid, newconname);
 
+	ObjectAddressSet(address, ConstraintRelationId, constraintOid);
+
 	ReleaseSysCache(tuple);
 
 	if (targetrelation)
 		relation_close(targetrelation, NoLock); /* close rel but keep lock */
 
-	return constraintOid;
+	return address;
 }
 
-Oid
+ObjectAddress
 RenameConstraint(RenameStmt *stmt)
 {
 	Oid			relid = InvalidOid;
@@ -2497,10 +2515,11 @@ RenameConstraint(RenameStmt *stmt)
  * Execute ALTER TABLE/INDEX/SEQUENCE/VIEW/MATERIALIZED VIEW/FOREIGN TABLE
  * RENAME
  */
-Oid
+ObjectAddress
 RenameRelation(RenameStmt *stmt)
 {
 	Oid			relid;
+	ObjectAddress address;
 
 	/*
 	 * Grab an exclusive lock on the target table, index, sequence, view,
@@ -2520,13 +2539,15 @@ RenameRelation(RenameStmt *stmt)
 		ereport(NOTICE,
 				(errmsg("relation \"%s\" does not exist, skipping",
 						stmt->relation->relname)));
-		return InvalidOid;
+		return InvalidObjectAddress;
 	}
 
 	/* Do the work */
 	RenameRelationInternal(relid, stmt->newname, false);
 
-	return relid;
+	ObjectAddressSet(address, RelationRelationId, relid);
+
+	return address;
 }
 
 /*
@@ -5702,7 +5723,7 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 	bool		check_rights;
 	bool		skip_build;
 	bool		quiet;
-	Oid			new_index;
+	ObjectAddress address;
 
 	Assert(IsA(stmt, IndexStmt));
 	Assert(!stmt->concurrent);
@@ -5717,13 +5738,13 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 	/* suppress notices when rebuilding existing index */
 	quiet = is_rebuild;
 
-	new_index = DefineIndex(RelationGetRelid(rel),
-							stmt,
-							InvalidOid, /* no predefined OID */
-							true,		/* is_alter_table */
-							check_rights,
-							skip_build,
-							quiet);
+	address = DefineIndex(RelationGetRelid(rel),
+						  stmt,
+						  InvalidOid,	/* no predefined OID */
+						  true, /* is_alter_table */
+						  check_rights,
+						  skip_build,
+						  quiet);
 
 	/*
 	 * If TryReuseIndex() stashed a relfilenode for us, we used it for the new
@@ -5733,7 +5754,7 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 	 */
 	if (OidIsValid(stmt->oldNode))
 	{
-		Relation	irel = index_open(new_index, NoLock);
+		Relation	irel = index_open(address.objectId, NoLock);
 
 		RelationPreserveStorage(irel->rd_node, true);
 		index_close(irel, NoLock);
@@ -10919,8 +10940,8 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 /*
  * Execute ALTER TABLE SET SCHEMA
  */
-Oid
-AlterTableNamespace(AlterObjectSchemaStmt *stmt)
+ObjectAddress
+AlterTableNamespace(AlterObjectSchemaStmt *stmt, Oid *oldschema)
 {
 	Relation	rel;
 	Oid			relid;
@@ -10928,6 +10949,7 @@ AlterTableNamespace(AlterObjectSchemaStmt *stmt)
 	Oid			nspOid;
 	RangeVar   *newrv;
 	ObjectAddresses *objsMoved;
+	ObjectAddress myself;
 
 	relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
 									 stmt->missing_ok, false,
@@ -10939,7 +10961,7 @@ AlterTableNamespace(AlterObjectSchemaStmt *stmt)
 		ereport(NOTICE,
 				(errmsg("relation \"%s\" does not exist, skipping",
 						stmt->relation->relname)));
-		return InvalidOid;
+		return InvalidObjectAddress;
 	}
 
 	rel = relation_open(relid, NoLock);
@@ -10972,10 +10994,15 @@ AlterTableNamespace(AlterObjectSchemaStmt *stmt)
 	AlterTableNamespaceInternal(rel, oldNspOid, nspOid, objsMoved);
 	free_object_addresses(objsMoved);
 
+	ObjectAddressSet(myself, RelationRelationId, relid);
+
+	if (oldschema)
+		*oldschema = oldNspOid;
+
 	/* close rel, but keep lock until commit */
 	relation_close(rel, NoLock);
 
-	return relid;
+	return myself;
 }
 
 /*