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, 120 insertions, 3 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 9cfa1700f43..57ef558c404 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/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 1.405 2008/09/09 18:58:08 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.406 2008/10/04 21:56:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -177,6 +177,27 @@ _copyAppend(Append *from)
 }
 
 /*
+ * _copyRecursiveUnion
+ */
+static RecursiveUnion *
+_copyRecursiveUnion(RecursiveUnion *from)
+{
+	RecursiveUnion	   *newnode = makeNode(RecursiveUnion);
+
+	/*
+	 * copy node superclass fields
+	 */
+	CopyPlanFields((Plan *) from, (Plan *) newnode);
+
+	/*
+	 * copy remainder of node
+	 */
+	COPY_SCALAR_FIELD(wtParam);
+
+	return newnode;
+}
+
+/*
  * _copyBitmapAnd
  */
 static BitmapAnd *
@@ -422,6 +443,49 @@ _copyValuesScan(ValuesScan *from)
 }
 
 /*
+ * _copyCteScan
+ */
+static CteScan *
+_copyCteScan(CteScan *from)
+{
+	CteScan *newnode = makeNode(CteScan);
+
+	/*
+	 * copy node superclass fields
+	 */
+	CopyScanFields((Scan *) from, (Scan *) newnode);
+
+	/*
+	 * copy remainder of node
+	 */
+	COPY_SCALAR_FIELD(ctePlanId);
+	COPY_SCALAR_FIELD(cteParam);
+
+	return newnode;
+}
+
+/*
+ * _copyWorkTableScan
+ */
+static WorkTableScan *
+_copyWorkTableScan(WorkTableScan *from)
+{
+	WorkTableScan *newnode = makeNode(WorkTableScan);
+
+	/*
+	 * copy node superclass fields
+	 */
+	CopyScanFields((Scan *) from, (Scan *) newnode);
+
+	/*
+	 * copy remainder of node
+	 */
+	COPY_SCALAR_FIELD(wtParam);
+
+	return newnode;
+}
+
+/*
  * CopyJoinFields
  *
  *		This function copies the fields of the Join node.  It is used by
@@ -1572,12 +1636,17 @@ _copyRangeTblEntry(RangeTblEntry *from)
 	COPY_SCALAR_FIELD(rtekind);
 	COPY_SCALAR_FIELD(relid);
 	COPY_NODE_FIELD(subquery);
+	COPY_SCALAR_FIELD(jointype);
+	COPY_NODE_FIELD(joinaliasvars);
 	COPY_NODE_FIELD(funcexpr);
 	COPY_NODE_FIELD(funccoltypes);
 	COPY_NODE_FIELD(funccoltypmods);
 	COPY_NODE_FIELD(values_lists);
-	COPY_SCALAR_FIELD(jointype);
-	COPY_NODE_FIELD(joinaliasvars);
+	COPY_STRING_FIELD(ctename);
+	COPY_SCALAR_FIELD(ctelevelsup);
+	COPY_SCALAR_FIELD(self_reference);
+	COPY_NODE_FIELD(ctecoltypes);
+	COPY_NODE_FIELD(ctecoltypmods);
 	COPY_NODE_FIELD(alias);
 	COPY_NODE_FIELD(eref);
 	COPY_SCALAR_FIELD(inh);
@@ -1632,6 +1701,36 @@ _copyRowMarkClause(RowMarkClause *from)
 	return newnode;
 }
 
+static WithClause *
+_copyWithClause(WithClause *from)
+{
+	WithClause *newnode = makeNode(WithClause);
+
+	COPY_NODE_FIELD(ctes);
+	COPY_SCALAR_FIELD(recursive);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+static CommonTableExpr *
+_copyCommonTableExpr(CommonTableExpr *from)
+{
+	CommonTableExpr *newnode = makeNode(CommonTableExpr);
+
+	COPY_STRING_FIELD(ctename);
+	COPY_NODE_FIELD(aliascolnames);
+	COPY_NODE_FIELD(ctequery);
+	COPY_LOCATION_FIELD(location);
+	COPY_SCALAR_FIELD(cterecursive);
+	COPY_SCALAR_FIELD(cterefcount);
+	COPY_NODE_FIELD(ctecolnames);
+	COPY_NODE_FIELD(ctecoltypes);
+	COPY_NODE_FIELD(ctecoltypmods);
+
+	return newnode;
+}
+
 static A_Expr *
 _copyAExpr(A_Expr *from)
 {
@@ -1931,6 +2030,8 @@ _copyQuery(Query *from)
 	COPY_SCALAR_FIELD(hasAggs);
 	COPY_SCALAR_FIELD(hasSubLinks);
 	COPY_SCALAR_FIELD(hasDistinctOn);
+	COPY_SCALAR_FIELD(hasRecursive);
+	COPY_NODE_FIELD(cteList);
 	COPY_NODE_FIELD(rtable);
 	COPY_NODE_FIELD(jointree);
 	COPY_NODE_FIELD(targetList);
@@ -1999,6 +2100,7 @@ _copySelectStmt(SelectStmt *from)
 	COPY_NODE_FIELD(whereClause);
 	COPY_NODE_FIELD(groupClause);
 	COPY_NODE_FIELD(havingClause);
+	COPY_NODE_FIELD(withClause);
 	COPY_NODE_FIELD(valuesLists);
 	COPY_NODE_FIELD(sortClause);
 	COPY_NODE_FIELD(limitOffset);
@@ -3104,6 +3206,9 @@ copyObject(void *from)
 		case T_Append:
 			retval = _copyAppend(from);
 			break;
+		case T_RecursiveUnion:
+			retval = _copyRecursiveUnion(from);
+			break;
 		case T_BitmapAnd:
 			retval = _copyBitmapAnd(from);
 			break;
@@ -3137,6 +3242,12 @@ copyObject(void *from)
 		case T_ValuesScan:
 			retval = _copyValuesScan(from);
 			break;
+		case T_CteScan:
+			retval = _copyCteScan(from);
+			break;
+		case T_WorkTableScan:
+			retval = _copyWorkTableScan(from);
+			break;
 		case T_Join:
 			retval = _copyJoin(from);
 			break;
@@ -3672,6 +3783,12 @@ copyObject(void *from)
 		case T_RowMarkClause:
 			retval = _copyRowMarkClause(from);
 			break;
+		case T_WithClause:
+			retval = _copyWithClause(from);
+			break;
+		case T_CommonTableExpr:
+			retval = _copyCommonTableExpr(from);
+			break;
 		case T_FkConstraint:
 			retval = _copyFkConstraint(from);
 			break;