Implement "WITH / WITHOID OIDS" clause for CREATE TABLE AS. This is

intended to allow application authors to insulate themselves from
changes to the default value of 'default_with_oids' in future releases
of PostgreSQL.

This patch also fixes a bug in the earlier implementation of the
'default_with_oids' GUC variable: code in gram.y should not examine
the value of GUC variables directly due to synchronization issues.

Author: Neil Conway

doc/src/sgml/ref/create_table_as.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_table_as.sgml,v 1.19 2003/12/13 23:59:07 neilc Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_table_as.sgml,v 1.20 2004/01/10 23:28:44 neilc Exp $
 PostgreSQL documentation
 -->
 
@@ -20,7 +20,7 @@ PostgreSQL documentation
 
  <refsynopsisdiv>
 <synopsis>
-CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable>table_name</replaceable> [ (<replaceable>column_name</replaceable> [, ...] ) ]
+CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable>table_name</replaceable> [ (<replaceable>column_name</replaceable> [, ...] ) ] [ [ WITH | WITHOUT ] OIDS ]
     AS <replaceable>query</replaceable>
 </synopsis>
  </refsynopsisdiv>
@@ -98,6 +98,20 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable>table_name
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><literal>WITH OIDS</literal></term>
+    <term><literal>WITHOUT OIDS</literal></term>
+     <listitem>
+      <para>
+       This optional clause specifies whether the table created by
+       <command>CREATE TABLE AS</command> should include OIDs. If
+       neither form of this clause if specified, the value of the
+       <varname>default_with_oids</varname> configuration parameter is
+       used.
+      </para>
+     </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><replaceable>query</replaceable></term>
     <listitem>
@@ -121,23 +135,30 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable>table_name
    This command is functionally similar to <xref
    linkend="sql-selectinto" endterm="sql-selectinto-title">, but it is
    preferred since it is less likely to be confused with other uses of
-   the <command>SELECT INTO</command> syntax.
+   the <command>SELECT INTO</> syntax. Furthermore, <command>CREATE
+   TABLE AS</command> offers a superset of the functionality offerred
+   by <command>SELECT INTO</command>.
   </para>
 
   <para>
-   Prior to <productname>PostgreSQL</> 7.5, <command>CREATE TABLE
-   AS</command> always included OIDs in the table it
+   Prior to <productname>PostgreSQL</productname> 7.5, <command>CREATE
+   TABLE AS</command> always included OIDs in the table it
    produced. Furthermore, these OIDs were newly generated: they were
    distinct from the OIDs of any of the rows in the source tables of
    the <command>SELECT</command> or <command>EXECUTE</command>
    statement. Therefore, if <command>CREATE TABLE AS</command> was
    frequently executed, the OID counter would be rapidly
-   incremented. As of <productname>PostgreSQL</> 7.5, the inclusion of
-   OIDs in the table generated by <command>CREATE TABLE AS</command>
-   is controlled by the <varname>default_with_oids</varname>
-   configuration variable. This variable currently defaults to true,
-   but will likely default to false in a future release of
-   <productname>PostgreSQL</>.
+   incremented. As of <productname>PostgresSQL</productname> 7.5,
+   the <command>CREATE TABLE AS</command> command allows the user to
+   explicitely specify whether OIDs should be included. If the
+   presence of OIDs is not explicitely specified,
+   the <varname>default_with_oids</varname> configuration variable is
+   used. While this variable currently defaults to true, the default
+   value may be changed in the future. Therefore, applications that
+   require OIDs in the table created by <command>CREATE TABLE
+   AS</command> should explicitely specify <literal>WITH
+   OIDS</literal> to ensure compatibility with future versions
+   of <productname>PostgreSQL</productname>.
   </para>
  </refsect1>
 

doc/src/sgml/runtime.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.229 2004/01/06 17:26:22 neilc Exp $
+$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.230 2004/01/10 23:28:43 neilc Exp $
 -->
 
 <Chapter Id="runtime">
@@ -2437,17 +2437,17 @@ dynamic_library_path = '/usr/local/lib/postgresql:/home/my_project/lib:$libdir'
       <term><varname>default_with_oids</varname> (<type>boolean</type>)</term>
       <listitem>
        <para>
-        This controls whether <command>CREATE TABLE</command> will
-        include OIDs in newly-created tables, if neither <literal>WITH
-        OIDS</literal> or <literal>WITHOUT OIDS</literal> have been
-        specified. It also determines whether OIDs will be included in
-        the table generated by <command>SELECT INTO</command> and
-        <command>CREATE TABLE AS</command>. In
+        This controls whether <command>CREATE TABLE</command>
+        and <command>CREATE TABLE AS</command> will include OIDs in
+        newly-created tables, if neither <literal>WITH OIDS</literal>
+        or <literal>WITHOUT OIDS</literal> have been specified. It
+        also determines whether OIDs will be included in the table
+        created by <command>SELECT INTO</command>. In
         <productname>PostgreSQL</productname> &version;
-        <varname>default_with_oids</varname> defaults to true. This is
-        also the behavior of previous versions of
-        <productname>PostgreSQL</productname>. However, assuming that
-        tables will contain OIDs by default is not
+        <varname>default_with_oids</varname> defaults to
+        true. This is also the behavior of previous versions
+        of <productname>PostgreSQL</productname>. However, assuming
+        that tables will contain OIDs by default is not
         encouraged. Therefore, this option will default to false in a
         future release of <productname>PostgreSQL</productname>.
        </para>

src/backend/commands/sequence.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.107 2004/01/07 18:56:25 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.108 2004/01/10 23:28:44 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -178,7 +178,7 @@ DefineSequence(CreateSeqStmt *seq)
 	stmt->relation = seq->sequence;
 	stmt->inhRelations = NIL;
 	stmt->constraints = NIL;
-	stmt->hasoids = false;
+	stmt->hasoids = MUST_NOT_HAVE_OIDS;
 	stmt->oncommit = ONCOMMIT_NOOP;
 
 	seqoid = DefineRelation(stmt, RELKIND_SEQUENCE);

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.94 2003/11/29 19:51:47 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.95 2004/01/10 23:28:44 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -47,6 +47,7 @@
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
+#include "utils/guc.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
 #include "utils/relcache.h"
@@ -185,7 +186,25 @@ DefineRelation(CreateStmt *stmt, char relkind)
 	 */
 	descriptor = BuildDescForRelation(schema);
 
-	descriptor->tdhasoid = (stmt->hasoids || parentHasOids);
+	if (parentHasOids)
+		descriptor->tdhasoid = true;
+	else
+	{
+		switch (stmt->hasoids)
+		{
+			case MUST_HAVE_OIDS:
+				descriptor->tdhasoid = true;
+				break;
+
+			case MUST_NOT_HAVE_OIDS:
+				descriptor->tdhasoid = false;
+				break;
+
+			case DEFAULT_OIDS:
+				descriptor->tdhasoid = default_with_oids;
+				break;
+		}
+	}
 
 	if (old_constraints != NIL)
 	{

src/backend/commands/typecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.51 2003/11/29 19:51:47 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.52 2004/01/10 23:28:44 neilc Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -1066,7 +1066,7 @@ DefineCompositeType(const RangeVar *typevar, List *coldeflist)
 	createStmt->tableElts = coldeflist;
 	createStmt->inhRelations = NIL;
 	createStmt->constraints = NIL;
-	createStmt->hasoids = false;
+	createStmt->hasoids = MUST_NOT_HAVE_OIDS;
 	createStmt->oncommit = ONCOMMIT_NOOP;
 
 	/*

src/backend/commands/view.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/view.c,v 1.79 2003/11/29 19:51:48 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/view.c,v 1.80 2004/01/10 23:28:44 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -141,7 +141,7 @@ DefineVirtualRelation(const RangeVar *relation, List *tlist, bool replace)
 		createStmt->tableElts = attrList;
 		createStmt->inhRelations = NIL;
 		createStmt->constraints = NIL;
-		createStmt->hasoids = false;
+		createStmt->hasoids = MUST_NOT_HAVE_OIDS;
 		createStmt->oncommit = ONCOMMIT_NOOP;
 
 		/*

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.225 2004/01/07 18:56:26 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.226 2004/01/10 23:28:44 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -593,14 +593,7 @@ InitPlan(QueryDesc *queryDesc, bool explainOnly)
 	if (operation == CMD_SELECT && parseTree->into != NULL)
 	{
 		do_select_into = true;
-
-		/*
-		 * The presence of OIDs in the result set of SELECT INTO is
-		 * controlled by the default_with_oids GUC parameter. The
-		 * behavior in versions of PostgreSQL prior to 7.5 is to
-		 * always include OIDs.
-		 */
-		estate->es_force_oids = default_with_oids;
+		estate->es_force_oids = parseTree->intoHasOids;
 	}
 
 	/*

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.275 2004/01/06 23:55:18 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.276 2004/01/10 23:28:44 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1549,6 +1549,7 @@ _copyQuery(Query *from)
 	COPY_NODE_FIELD(utilityStmt);
 	COPY_SCALAR_FIELD(resultRelation);
 	COPY_NODE_FIELD(into);
+	COPY_SCALAR_FIELD(intoHasOids);
 	COPY_SCALAR_FIELD(hasAggs);
 	COPY_SCALAR_FIELD(hasSubLinks);
 	COPY_NODE_FIELD(rtable);
@@ -1623,6 +1624,7 @@ _copySelectStmt(SelectStmt *from)
 	COPY_NODE_FIELD(distinctClause);
 	COPY_NODE_FIELD(into);
 	COPY_NODE_FIELD(intoColNames);
+	COPY_SCALAR_FIELD(intoHasOids);
 	COPY_NODE_FIELD(targetList);
 	COPY_NODE_FIELD(fromClause);
 	COPY_NODE_FIELD(whereClause);

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.213 2004/01/06 23:55:18 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.214 2004/01/10 23:28:45 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -604,6 +604,7 @@ _equalQuery(Query *a, Query *b)
 	COMPARE_NODE_FIELD(utilityStmt);
 	COMPARE_SCALAR_FIELD(resultRelation);
 	COMPARE_NODE_FIELD(into);
+	COMPARE_SCALAR_FIELD(intoHasOids);
 	COMPARE_SCALAR_FIELD(hasAggs);
 	COMPARE_SCALAR_FIELD(hasSubLinks);
 	COMPARE_NODE_FIELD(rtable);
@@ -667,6 +668,7 @@ _equalSelectStmt(SelectStmt *a, SelectStmt *b)
 	COMPARE_NODE_FIELD(distinctClause);
 	COMPARE_NODE_FIELD(into);
 	COMPARE_NODE_FIELD(intoColNames);
+	COMPARE_SCALAR_FIELD(intoHasOids);
 	COMPARE_NODE_FIELD(targetList);
 	COMPARE_NODE_FIELD(fromClause);
 	COMPARE_NODE_FIELD(whereClause);

src/backend/parser/analyze.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.293 2004/01/05 20:58:58 neilc Exp $
+ *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.294 2004/01/10 23:28:45 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,6 +41,7 @@
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
+#include "utils/guc.h"
 #include "utils/lsyscache.h"
 #include "utils/relcache.h"
 #include "utils/syscache.h"
@@ -1974,6 +1975,21 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
 	if (stmt->intoColNames)
 		applyColumnNames(qry->targetList, stmt->intoColNames);
 
+	switch (stmt->intoHasOids)
+	{
+		case MUST_HAVE_OIDS:
+			qry->intoHasOids = true;
+			break;
+
+		case MUST_NOT_HAVE_OIDS:
+			qry->intoHasOids = false;
+			break;
+
+		case DEFAULT_OIDS:
+			qry->intoHasOids = default_with_oids;
+			break;
+	}
+
 	/* mark column origins */
 	markTargetListOrigins(pstate, qry->targetList);