Re: ALTER TYPE RENAME

Tom Lane wrote:
> Hm, I'm not entirely sure if you got the point or not.  For either
> relations or composite types, there is both a pg_class entry and a
> pg_type entry, and their names *must* stay in sync.  We could allow
> people to rename both entries using either ALTER TABLE or ALTER TYPE,
> but the general consensus seems to be that ALTER TYPE should be used
> for composite types and ALTER TABLE for tables/views/etc.  The fact
> that there's a pg_class entry for a composite type is really an
> implementation detail that would best not be exposed to users, so
> enforcing the use of the appropriate command seems reasonable to me.
>
>             regards, tom lane
>
Yes, that's exactly what I meant (my language skills are not best).

Anyway, I am sending second version of the patch. Changes are:
 - renamed TypeRename function to RenameTypeInternal and changed its
header comment
 - throw error when using ALTER TYPE to rename rowtype
 - split function renamerel to RenameRelation and RenameRelationInternal
where RenameRelation does permission checks and stuff and also checks if
it's not used for composite types and RenameRelationInternal  does the
actual rename. And I also did a little cleanup in those functions
(removed unused code and changed some hardcoded relkind types to globaly
predefined constants)
 - RenameType now calls RenameRelationInternal  for composite types
(which calls RenameTypeInternal automatically)

Any other comments ?

--
Regards
Petr Jelinek (PJMODOS)

Index: doc/src/sgml/ref/alter_type.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/ref/alter_type.sgml,v
retrieving revision 1.4
diff -c -r1.4 alter_type.sgml
*** doc/src/sgml/ref/alter_type.sgml    16 Sep 2006 00:30:16 -0000    1.4
--- doc/src/sgml/ref/alter_type.sgml    29 Sep 2007 05:43:14 -0000
***************
*** 26,31 ****
--- 26,32 ----
    <synopsis>
  ALTER TYPE <replaceable class="PARAMETER">name</replaceable> OWNER TO <replaceable
class="PARAMETER">new_owner</replaceable> 
  ALTER TYPE <replaceable class="PARAMETER">name</replaceable> SET SCHEMA <replaceable
class="PARAMETER">new_schema</replaceable>
+ ALTER TYPE <replaceable class="PARAMETER">name</replaceable> RNAME TO <replaceable
class="PARAMETER">new_name</replaceable>
    </synopsis>
   </refsynopsisdiv>

***************
*** 83,88 ****
--- 84,98 ----
        </listitem>
       </varlistentry>

+      <varlistentry>
+       <term><replaceable class="PARAMETER">new_name</replaceable></term>
+       <listitem>
+        <para>
+         The new name for the type.
+        </para>
+       </listitem>
+      </varlistentry>
+
      </variablelist>
     </para>
    </refsect1>
Index: src/backend/catalog/pg_type.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/catalog/pg_type.c,v
retrieving revision 1.113
diff -c -r1.113 pg_type.c
*** src/backend/catalog/pg_type.c    12 May 2007 00:54:59 -0000    1.113
--- src/backend/catalog/pg_type.c    30 Sep 2007 04:20:03 -0000
***************
*** 552,566 ****
  }

  /*
!  * TypeRename
   *        This renames a type, as well as any associated array type.
   *
!  * Note: this isn't intended to be a user-exposed function; it doesn't check
!  * permissions etc.  (Perhaps TypeRenameInternal would be a better name.)
!  * Currently this is only used for renaming table rowtypes.
   */
  void
! TypeRename(Oid typeOid, const char *newTypeName, Oid typeNamespace)
  {
      Relation    pg_type_desc;
      HeapTuple    tuple;
--- 552,567 ----
  }

  /*
!  * RenameTypeInternal
   *        This renames a type, as well as any associated array type.
   *
!  * Caller must have already checked privileges.
!  *
!  * Currently this is used for renaming table rowtypes and for
!  * ALTER TYPE RENAME TO command.
   */
  void
! RenameTypeInternal(Oid typeOid, const char *newTypeName, Oid typeNamespace)
  {
      Relation    pg_type_desc;
      HeapTuple    tuple;
***************
*** 606,612 ****
      {
          char   *arrname = makeArrayTypeName(newTypeName, typeNamespace);

!         TypeRename(arrayOid, arrname, typeNamespace);
          pfree(arrname);
      }
  }
--- 607,613 ----
      {
          char   *arrname = makeArrayTypeName(newTypeName, typeNamespace);

!         RenameTypeInternal(arrayOid, arrname, typeNamespace);
          pfree(arrname);
      }
  }
***************
*** 706,712 ****
      newname = makeArrayTypeName(typeName, typeNamespace);

      /* Apply the rename */
!     TypeRename(typeOid, newname, typeNamespace);

      /*
       * We must bump the command counter so that any subsequent use of
--- 707,713 ----
      newname = makeArrayTypeName(typeName, typeNamespace);

      /* Apply the rename */
!     RenameTypeInternal(typeOid, newname, typeNamespace);

      /*
       * We must bump the command counter so that any subsequent use of
Index: src/backend/commands/alter.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/commands/alter.c,v
retrieving revision 1.25
diff -c -r1.25 alter.c
*** src/backend/commands/alter.c    21 Aug 2007 01:11:14 -0000    1.25
--- src/backend/commands/alter.c    30 Sep 2007 03:53:05 -0000
***************
*** 117,123 ****
                                  aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
                                              get_namespace_name(namespaceId));

!                             renamerel(relid, stmt->newname, stmt->renameType);
                              break;
                          }
                      case OBJECT_COLUMN:
--- 117,123 ----
                                  aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
                                              get_namespace_name(namespaceId));

!                             RenameRelation(relid, stmt->newname, stmt->renameType);
                              break;
                          }
                      case OBJECT_COLUMN:
***************
*** 154,159 ****
--- 154,164 ----
              RenameTSConfiguration(stmt->object, stmt->newname);
              break;

+         case OBJECT_TYPE:
+         case OBJECT_DOMAIN:
+             RenameType(stmt->object, stmt->newname);
+             break;
+
          default:
              elog(ERROR, "unrecognized rename stmt type: %d",
                   (int) stmt->renameType);
Index: src/backend/commands/tablecmds.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/commands/tablecmds.c,v
retrieving revision 1.233
diff -c -r1.233 tablecmds.c
*** src/backend/commands/tablecmds.c    29 Sep 2007 17:18:58 -0000    1.233
--- src/backend/commands/tablecmds.c    30 Sep 2007 03:55:31 -0000
***************
*** 1612,1637 ****
      relation_close(targetrelation, NoLock);        /* close rel but keep lock */
  }

  /*
!  *        renamerel        - change the name of a relation
!  *
!  *        XXX - When renaming sequences, we don't bother to modify the
!  *              sequence name that is stored within the sequence itself
!  *              (this would cause problems with MVCC). In the future,
!  *              the sequence name should probably be removed from the
!  *              sequence, AFAIK there's no need for it to be there.
   */
  void
! renamerel(Oid myrelid, const char *newrelname, ObjectType reltype)
  {
      Relation    targetrelation;
-     Relation    relrelation;    /* for RELATION relation */
-     HeapTuple    reltup;
-     Form_pg_class relform;
      Oid            namespaceId;
-     char       *oldrelname;
      char        relkind;
-     bool        relhastriggers;

      /*
       * Grab an exclusive lock on the target table, index, sequence or
--- 1612,1627 ----
      relation_close(targetrelation, NoLock);        /* close rel but keep lock */
  }

+
  /*
!  * Execute ALTER TABLE/VIEW/SEQUENCE RENAME
   */
  void
! RenameRelation(Oid myrelid, const char *newrelname, ObjectType reltype)
  {
      Relation    targetrelation;
      Oid            namespaceId;
      char        relkind;

      /*
       * Grab an exclusive lock on the target table, index, sequence or
***************
*** 1639,1645 ****
       */
      targetrelation = relation_open(myrelid, AccessExclusiveLock);

-     oldrelname = pstrdup(RelationGetRelationName(targetrelation));
      namespaceId = RelationGetNamespace(targetrelation);

      if (!allowSystemTableMods && IsSystemRelation(targetrelation))
--- 1629,1634 ----
***************
*** 1654,1672 ****
       * view.
       */
      relkind = targetrelation->rd_rel->relkind;
!     if (reltype == OBJECT_SEQUENCE && relkind != 'S')
          ereport(ERROR,
                  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                   errmsg("\"%s\" is not a sequence",
                          RelationGetRelationName(targetrelation))));

!     if (reltype == OBJECT_VIEW && relkind != 'v')
          ereport(ERROR,
                  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                   errmsg("\"%s\" is not a view",
                          RelationGetRelationName(targetrelation))));

!     relhastriggers = (targetrelation->rd_rel->reltriggers > 0);

      /*
       * Find relation's pg_class tuple, and make sure newrelname isn't in use.
--- 1643,1702 ----
       * view.
       */
      relkind = targetrelation->rd_rel->relkind;
!     if (reltype == OBJECT_SEQUENCE && relkind != RELKIND_SEQUENCE)
          ereport(ERROR,
                  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                   errmsg("\"%s\" is not a sequence",
                          RelationGetRelationName(targetrelation))));

!     if (reltype == OBJECT_VIEW && relkind != RELKIND_VIEW)
          ereport(ERROR,
                  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                   errmsg("\"%s\" is not a view",
                          RelationGetRelationName(targetrelation))));

!     /*
!      * Don't allow ALTER TABLE on composite types.
!      * We want people to use ALTER TYPE for that.
!      */
!     if (relkind == RELKIND_COMPOSITE_TYPE)
!         ereport(ERROR,
!                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
!                  errmsg("\"%s\" is a composite type",
!                         RelationGetRelationName(targetrelation)),
!                  errhint("Use ALTER TYPE RENAME TO instead.")));
!
!     /* Do the work */
!     RenameRelationInternal(myrelid, newrelname, namespaceId);
!
!     /*
!      * Close rel, but keep exclusive lock!
!      */
!     relation_close(targetrelation, NoLock);
! }
!
! /*
!  *        RenameRelationInternal - change the name of a relation
!  *
!  *        XXX - When renaming sequences, we don't bother to modify the
!  *              sequence name that is stored within the sequence itself
!  *              (this would cause problems with MVCC). In the future,
!  *              the sequence name should probably be removed from the
!  *              sequence, AFAIK there's no need for it to be there.
!  */
! void
! RenameRelationInternal(Oid myrelid, const char *newrelname, Oid namespaceId)
! {
!     Relation    targetrelation;
!     Relation    relrelation;    /* for RELATION relation */
!     HeapTuple    reltup;
!     Form_pg_class relform;
!
!     /*
!      * Grab an exclusive lock on the target table, index, sequence or
!      * view, which we will NOT release until end of transaction.
!      */
!     targetrelation = relation_open(myrelid, AccessExclusiveLock);

      /*
       * Find relation's pg_class tuple, and make sure newrelname isn't in use.
***************
*** 1704,1710 ****
       * Also rename the associated type, if any.
       */
      if (OidIsValid(targetrelation->rd_rel->reltype))
!         TypeRename(targetrelation->rd_rel->reltype, newrelname, namespaceId);

      /*
       * Close rel, but keep exclusive lock!
--- 1734,1740 ----
       * Also rename the associated type, if any.
       */
      if (OidIsValid(targetrelation->rd_rel->reltype))
!         RenameTypeInternal(targetrelation->rd_rel->reltype, newrelname, namespaceId);

      /*
       * Close rel, but keep exclusive lock!
Index: src/backend/commands/typecmds.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/commands/typecmds.c,v
retrieving revision 1.108
diff -c -r1.108 typecmds.c
*** src/backend/commands/typecmds.c    29 Sep 2007 17:18:58 -0000    1.108
--- src/backend/commands/typecmds.c    30 Sep 2007 04:36:08 -0000
***************
*** 2654,2656 ****
--- 2654,2723 ----
      if (OidIsValid(arrayOid))
          AlterTypeNamespaceInternal(arrayOid, nspOid, true, true);
  }
+
+
+ /*
+  * Execute ALTER TYPE RENAME
+  */
+ void
+ RenameType(List *names, const char *newTypeName)
+ {
+     TypeName   *typename;
+     Oid            typeOid;
+     Relation    rel;
+     HeapTuple    tup;
+     Form_pg_type typTup;
+
+     /* Make a TypeName so we can use standard type lookup machinery */
+     typename = makeTypeNameFromNameList(names);
+     typeOid = typenameTypeId(NULL, typename);
+
+     /* Look up the type in the type table */
+     rel = heap_open(TypeRelationId, RowExclusiveLock);
+
+     tup = SearchSysCacheCopy(TYPEOID,
+                              ObjectIdGetDatum(typeOid),
+                              0, 0, 0);
+     if (!HeapTupleIsValid(tup))
+         elog(ERROR, "cache lookup failed for type %u", typeOid);
+     typTup = (Form_pg_type) GETSTRUCT(tup);
+
+     /* check permissions on type */
+     if (!pg_type_ownercheck(typeOid, GetUserId()))
+         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TYPE,
+                        format_type_be(typeOid));
+
+     /*
+      * If it's a composite type, we need to check that it really is a
+      * free-standing composite type, and not a table's rowtype. We
+      * want people to use ALTER TABLE not ALTER TYPE for that case.
+      */
+     if (typTup->typtype == TYPTYPE_COMPOSITE &&
+         get_rel_relkind(typTup->typrelid) != RELKIND_COMPOSITE_TYPE)
+         ereport(ERROR,
+                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                  errmsg("\"%s\" is a table's row type",
+                         TypeNameToString(typename))));
+
+     /* don't allow direct alteration of array types, either */
+     if (OidIsValid(typTup->typelem) &&
+         get_array_type(typTup->typelem) == typeOid)
+         ereport(ERROR,
+                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                  errmsg("cannot alter array type %s",
+                         format_type_be(typeOid)),
+                  errhint("You can alter type %s, which will alter the array type as well.",
+                          format_type_be(typTup->typelem))));
+
+     /*
+      * If type is composite type we need to rename associated relation too.
+      * RenameRelationInternal will call RenameTypeInternal automatically.
+      */
+     if (typTup->typtype == TYPTYPE_COMPOSITE)
+         RenameRelationInternal(typTup->typrelid, newTypeName, typTup->typnamespace);
+     else
+         RenameTypeInternal(typeOid, newTypeName, typTup->typnamespace);
+
+     /* Clean up */
+     heap_close(rel, RowExclusiveLock);
+ }
Index: src/backend/parser/gram.y
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/parser/gram.y,v
retrieving revision 2.603
diff -c -r2.603 gram.y
*** src/backend/parser/gram.y    24 Sep 2007 01:29:28 -0000    2.603
--- src/backend/parser/gram.y    29 Sep 2007 05:13:21 -0000
***************
*** 4748,4753 ****
--- 4748,4761 ----
                      n->newname = $8;
                      $$ = (Node *)n;
                  }
+             | ALTER TYPE_P any_name RENAME TO name
+                 {
+                     RenameStmt *n = makeNode(RenameStmt);
+                     n->renameType = OBJECT_TYPE;
+                     n->object = $3;
+                     n->newname = $6;
+                     $$ = (Node *)n;
+                 }
          ;

  opt_column: COLUMN                                    { $$ = COLUMN; }
Index: src/include/catalog/pg_type.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/catalog/pg_type.h,v
retrieving revision 1.188
diff -c -r1.188 pg_type.h
*** src/include/catalog/pg_type.h    3 Sep 2007 02:30:45 -0000    1.188
--- src/include/catalog/pg_type.h    29 Sep 2007 23:04:57 -0000
***************
*** 678,684 ****
                           Node *defaultExpr,
                           bool rebuild);

! extern void TypeRename(Oid typeOid, const char *newTypeName,
                         Oid typeNamespace);

  extern char *makeArrayTypeName(const char *typeName, Oid typeNamespace);
--- 678,684 ----
                           Node *defaultExpr,
                           bool rebuild);

! extern void RenameTypeInternal(Oid typeOid, const char *newTypeName,
                         Oid typeNamespace);

  extern char *makeArrayTypeName(const char *typeName, Oid typeNamespace);
Index: src/include/commands/tablecmds.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/commands/tablecmds.h,v
retrieving revision 1.34
diff -c -r1.34 tablecmds.h
*** src/include/commands/tablecmds.h    3 Jul 2007 01:30:37 -0000    1.34
--- src/include/commands/tablecmds.h    30 Sep 2007 03:49:44 -0000
***************
*** 42,51 ****
            bool recurse,
            bool recursing);

! extern void renamerel(Oid myrelid,
            const char *newrelname,
            ObjectType reltype);

  extern void find_composite_type_dependencies(Oid typeOid,
                                               const char *origTblName,
                                               const char *origTypeName);
--- 42,55 ----
            bool recurse,
            bool recursing);

! extern void RenameRelation(Oid myrelid,
            const char *newrelname,
            ObjectType reltype);

+ extern void RenameRelationInternal(Oid myrelid,
+           const char *newrelname,
+           Oid namespaceId);
+
  extern void find_composite_type_dependencies(Oid typeOid,
                                               const char *origTblName,
                                               const char *origTypeName);
Index: src/include/commands/typecmds.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/commands/typecmds.h,v
retrieving revision 1.19
diff -c -r1.19 typecmds.h
*** src/include/commands/typecmds.h    11 May 2007 17:57:14 -0000    1.19
--- src/include/commands/typecmds.h    29 Sep 2007 05:11:57 -0000
***************
*** 43,46 ****
--- 43,48 ----
                                         bool isImplicitArray,
                                         bool errorOnTableType);

+ extern void RenameType(List *names, const char *newTypeName);
+
  #endif   /* TYPECMDS_H */