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, 25 insertions, 0 deletions

diff --git a/src/include/executor/nodeRecursiveunion.h b/src/include/executor/nodeRecursiveunion.h
new file mode 100644
index 00000000000..561f82a69b3
--- /dev/null
+++ b/src/include/executor/nodeRecursiveunion.h
@@ -0,0 +1,25 @@
+/*-------------------------------------------------------------------------
+ *
+ * nodeRecursiveunion.h
+ *
+ *
+ *
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/executor/nodeRecursiveunion.h,v 1.1 2008/10/04 21:56:55 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef NODERECURSIVEUNION_H
+#define NODERECURSIVEUNION_H
+
+#include "nodes/execnodes.h"
+
+extern int	ExecCountSlotsRecursiveUnion(RecursiveUnion *node);
+extern RecursiveUnionState *ExecInitRecursiveUnion(RecursiveUnion *node, EState *estate, int eflags);
+extern TupleTableSlot *ExecRecursiveUnion(RecursiveUnionState *node);
+extern void ExecEndRecursiveUnion(RecursiveUnionState *node);
+extern void ExecRecursiveUnionReScan(RecursiveUnionState *node, ExprContext *exprCtxt);
+
+#endif   /* NODERECURSIVEUNION_H */