4 files changed, 32 insertions, 13 deletions
diff --git a/src/include/commands/portalcmds.h b/src/include/commands/portalcmds.h
index 3f2a4221add..74855ddf605 100644
--- a/src/include/commands/portalcmds.h
+++ b/src/include/commands/portalcmds.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: portalcmds.h,v 1.5 2003/03/10 03:53:51 tgl Exp $
+ * $Id: portalcmds.h,v 1.6 2003/03/11 19:40:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,10 +19,12 @@
 
 extern void PerformCursorOpen(DeclareCursorStmt *stmt, CommandDest dest);
 
-extern void PerformPortalFetch(char *name, bool forward, long count,
-				   CommandDest dest, char *completionTag);
+extern void PerformPortalFetch(FetchStmt *stmt, CommandDest dest,
+							   char *completionTag);
 
-extern long DoPortalFetch(Portal portal, bool forward, long count,
+extern long DoPortalFetch(Portal portal,
+						  FetchDirection fdirection,
+						  long count,
 						  CommandDest dest);
 
 extern void PerformPortalClose(char *name);
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 785d21718b2..40a696e2976 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: executor.h,v 1.90 2003/03/10 03:53:51 tgl Exp $
+ * $Id: executor.h,v 1.91 2003/03/11 19:40:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -86,6 +86,7 @@ extern void ExecutorStart(QueryDesc *queryDesc);
 extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc,
 			ScanDirection direction, long count);
 extern void ExecutorEnd(QueryDesc *queryDesc);
+extern void ExecutorRewind(QueryDesc *queryDesc);
 extern void ExecCheckRTPerms(List *rangeTable, CmdType operation);
 extern void ExecEndPlan(PlanState *planstate, EState *estate);
 extern void ExecConstraints(const char *caller, ResultRelInfo *resultRelInfo,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index c84348ded9e..216ed04c762 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.232 2003/03/10 03:53:51 tgl Exp $
+ * $Id: parsenodes.h,v 1.233 2003/03/11 19:40:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1228,16 +1228,21 @@ typedef struct ClosePortalStmt
  */
 typedef enum FetchDirection
 {
+	/* for these, howMany is how many rows to fetch; FETCH_ALL means ALL */
 	FETCH_FORWARD,
-	FETCH_BACKWARD
-	/* ABSOLUTE someday? */
+	FETCH_BACKWARD,
+	/* for these, howMany indicates a position; only one row is fetched */
+	FETCH_ABSOLUTE,
+	FETCH_RELATIVE
 } FetchDirection;
 
+#define FETCH_ALL	LONG_MAX
+
 typedef struct FetchStmt
 {
 	NodeTag		type;
 	FetchDirection direction;	/* see above */
-	long		howMany;		/* number of rows */
+	long		howMany;		/* number of rows, or position argument */
 	char	   *portalname;		/* name of portal (cursor) */
 	bool		ismove;			/* TRUE if MOVE */
 } FetchStmt;
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 21469dd52df..c9ca8547ce2 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: portal.h,v 1.38 2003/03/10 03:53:52 tgl Exp $
+ * $Id: portal.h,v 1.39 2003/03/11 19:40:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,10 +27,21 @@ typedef struct PortalData
 	char	   *name;			/* Portal's name */
 	MemoryContext heap;			/* subsidiary memory */
 	QueryDesc  *queryDesc;		/* Info about query associated with portal */
-	bool		backwardOK;		/* is fetch backwards allowed at all? */
-	bool		atStart;		/* T => fetch backwards is not allowed now */
-	bool		atEnd;			/* T => fetch forwards is not allowed now */
 	void		(*cleanup) (Portal);	/* Cleanup routine (optional) */
+	bool		backwardOK;		/* is fetch backwards allowed? */
+	/*
+	 * atStart, atEnd and portalPos indicate the current cursor position.
+	 * portalPos is zero before the first row, N after fetching N'th row of
+	 * query.  After we run off the end, portalPos = # of rows in query, and
+	 * atEnd is true.  If portalPos overflows, set posOverflow (this causes
+	 * us to stop relying on its value for navigation).  Note that atStart
+	 * implies portalPos == 0, but not the reverse (portalPos could have
+	 * overflowed).
+	 */
+	bool		atStart;
+	bool		atEnd;
+	bool		posOverflow;
+	long		portalPos;
 } PortalData;
 
 /*