Date: Tue, 10 Mar 2020 11:41:20 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: time for catalog/pg_cast.c?
Message-ID: <20200310144120.GA13226@alvherre.pgsql>
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I would even say that DropCastById belongs in the new file, which is
just the attached.  However, none of the Drop.*ById or Remove.*ById
functions seem to be in backend/catalog/ at all, and moving just a
single one seems to make things even more inconsistent.  I think all
these catalog-accessing functions should be in backend/catalog/ but I'm
not in a hurry to patch half of backend/commands/ to move them all.

(I think the current arrangement is just fallout from having created the
dependency.c system to drop objects, which rid us of a bunch of bespoke
deletion-handling code.)

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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diff --git a/src/backend/catalog/pg_cast.c b/src/backend/catalog/pg_cast.c
index 3854455637..bd2a369aad 100644
--- a/src/backend/catalog/pg_cast.c
+++ b/src/backend/catalog/pg_cast.c
@@ -14,7 +14,9 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
+#include "access/skey.h"
 #include "access/table.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
@@ -24,6 +26,7 @@
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "utils/builtins.h"
+#include "utils/fmgroids.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 
@@ -121,3 +124,29 @@ CastCreate(Oid sourcetypeid, Oid targettypeid, Oid funcid, char castcontext,
 
 	return myself;
 }
+
+void
+DropCastById(Oid castOid)
+{
+	Relation	relation;
+	ScanKeyData scankey;
+	SysScanDesc scan;
+	HeapTuple	tuple;
+
+	relation = table_open(CastRelationId, RowExclusiveLock);
+
+	ScanKeyInit(&scankey,
+				Anum_pg_cast_oid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(castOid));
+	scan = systable_beginscan(relation, CastOidIndexId, true,
+							  NULL, 1, &scankey);
+
+	tuple = systable_getnext(scan);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "could not find tuple for cast %u", castOid);
+	CatalogTupleDelete(relation, &tuple->t_self);
+
+	systable_endscan(scan);
+	table_close(relation, RowExclusiveLock);
+}
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 5eac55aaca..355e93840a 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -1645,33 +1645,6 @@ CreateCast(CreateCastStmt *stmt)
 	return myself;
 }
 
-void
-DropCastById(Oid castOid)
-{
-	Relation	relation;
-	ScanKeyData scankey;
-	SysScanDesc scan;
-	HeapTuple	tuple;
-
-	relation = table_open(CastRelationId, RowExclusiveLock);
-
-	ScanKeyInit(&scankey,
-				Anum_pg_cast_oid,
-				BTEqualStrategyNumber, F_OIDEQ,
-				ObjectIdGetDatum(castOid));
-	scan = systable_beginscan(relation, CastOidIndexId, true,
-							  NULL, 1, &scankey);
-
-	tuple = systable_getnext(scan);
-	if (!HeapTupleIsValid(tuple))
-		elog(ERROR, "could not find tuple for cast %u", castOid);
-	CatalogTupleDelete(relation, &tuple->t_self);
-
-	systable_endscan(scan);
-	table_close(relation, RowExclusiveLock);
-}
-
-
 static void
 check_transform_function(Form_pg_proc procstruct)
 {
diff --git a/src/include/catalog/pg_cast.h b/src/include/catalog/pg_cast.h
index 2620ff40f0..78ba395f17 100644
--- a/src/include/catalog/pg_cast.h
+++ b/src/include/catalog/pg_cast.h
@@ -95,5 +95,6 @@ extern ObjectAddress CastCreate(Oid sourcetypeid,
 								char castcontext,
 								char castmethod,
 								DependencyType behavior);
+extern void DropCastById(Oid castOid);
 
 #endif							/* PG_CAST_H */
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index c77c9a6ed5..1d22cc8083 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -56,7 +56,6 @@ extern ObjectAddress CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt
 extern void RemoveFunctionById(Oid funcOid);
 extern ObjectAddress AlterFunction(ParseState *pstate, AlterFunctionStmt *stmt);
 extern ObjectAddress CreateCast(CreateCastStmt *stmt);
-extern void DropCastById(Oid castOid);
 extern ObjectAddress CreateTransform(CreateTransformStmt *stmt);
 extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,

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