Implement SQL-standard WITH clauses, including WITH RECURSIVE.

There are some unimplemented aspects: recursive queries must use UNION ALL
(should allow UNION too), and we don't have SEARCH or CYCLE clauses.
These might or might not get done for 8.4, but even without them it's a
pretty useful feature.

There are also a couple of small loose ends and definitional quibbles,
which I'll send a memo about to pgsql-hackers shortly.  But let's land
the patch now so we can get on with other development.

Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane

1 files changed, 43 insertions, 3 deletions

diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index f0939b4777d..f01ebe33e87 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -22,7 +22,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.331 2008/09/01 20:42:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.332 2008/10/04 21:56:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -808,6 +808,8 @@ _equalQuery(Query *a, Query *b)
 	COMPARE_SCALAR_FIELD(hasAggs);
 	COMPARE_SCALAR_FIELD(hasSubLinks);
 	COMPARE_SCALAR_FIELD(hasDistinctOn);
+	COMPARE_SCALAR_FIELD(hasRecursive);
+	COMPARE_NODE_FIELD(cteList);
 	COMPARE_NODE_FIELD(rtable);
 	COMPARE_NODE_FIELD(jointree);
 	COMPARE_NODE_FIELD(targetList);
@@ -868,6 +870,7 @@ _equalSelectStmt(SelectStmt *a, SelectStmt *b)
 	COMPARE_NODE_FIELD(whereClause);
 	COMPARE_NODE_FIELD(groupClause);
 	COMPARE_NODE_FIELD(havingClause);
+	COMPARE_NODE_FIELD(withClause);
 	COMPARE_NODE_FIELD(valuesLists);
 	COMPARE_NODE_FIELD(sortClause);
 	COMPARE_NODE_FIELD(limitOffset);
@@ -1932,12 +1935,17 @@ _equalRangeTblEntry(RangeTblEntry *a, RangeTblEntry *b)
 	COMPARE_SCALAR_FIELD(rtekind);
 	COMPARE_SCALAR_FIELD(relid);
 	COMPARE_NODE_FIELD(subquery);
+	COMPARE_SCALAR_FIELD(jointype);
+	COMPARE_NODE_FIELD(joinaliasvars);
 	COMPARE_NODE_FIELD(funcexpr);
 	COMPARE_NODE_FIELD(funccoltypes);
 	COMPARE_NODE_FIELD(funccoltypmods);
 	COMPARE_NODE_FIELD(values_lists);
-	COMPARE_SCALAR_FIELD(jointype);
-	COMPARE_NODE_FIELD(joinaliasvars);
+	COMPARE_STRING_FIELD(ctename);
+	COMPARE_SCALAR_FIELD(ctelevelsup);
+	COMPARE_SCALAR_FIELD(self_reference);
+	COMPARE_NODE_FIELD(ctecoltypes);
+	COMPARE_NODE_FIELD(ctecoltypmods);
 	COMPARE_NODE_FIELD(alias);
 	COMPARE_NODE_FIELD(eref);
 	COMPARE_SCALAR_FIELD(inh);
@@ -1970,6 +1978,32 @@ _equalRowMarkClause(RowMarkClause *a, RowMarkClause *b)
 }
 
 static bool
+_equalWithClause(WithClause *a, WithClause *b)
+{
+	COMPARE_NODE_FIELD(ctes);
+	COMPARE_SCALAR_FIELD(recursive);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
+static bool
+_equalCommonTableExpr(CommonTableExpr *a, CommonTableExpr *b)
+{
+	COMPARE_STRING_FIELD(ctename);
+	COMPARE_NODE_FIELD(aliascolnames);
+	COMPARE_NODE_FIELD(ctequery);
+	COMPARE_LOCATION_FIELD(location);
+	COMPARE_SCALAR_FIELD(cterecursive);
+	COMPARE_SCALAR_FIELD(cterefcount);
+	COMPARE_NODE_FIELD(ctecolnames);
+	COMPARE_NODE_FIELD(ctecoltypes);
+	COMPARE_NODE_FIELD(ctecoltypmods);
+
+	return true;
+}
+
+static bool
 _equalFkConstraint(FkConstraint *a, FkConstraint *b)
 {
 	COMPARE_STRING_FIELD(constr_name);
@@ -2593,6 +2627,12 @@ equal(void *a, void *b)
 		case T_RowMarkClause:
 			retval = _equalRowMarkClause(a, b);
 			break;
+		case T_WithClause:
+			retval = _equalWithClause(a, b);
+			break;
+		case T_CommonTableExpr:
+			retval = _equalCommonTableExpr(a, b);
+			break;
 		case T_FkConstraint:
 			retval = _equalFkConstraint(a, b);
 			break;