Make SELECT FOR UPDATE/SHARE work on inheritance trees, by having the plan

return the tableoid as well as the ctid for any FOR UPDATE targets that
have child tables.  All child tables are listed in the ExecRowMark list,
but the executor just skips the ones that didn't produce the current row.

Curiously, this longstanding restriction doesn't seem to have been documented
anywhere; so no doc changes.

1 files changed, 11 insertions, 2 deletions

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 5e112d178ba..1edd094dbf6 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.377 2008/10/31 08:39:22 heikki Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.378 2008/11/15 19:43:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -700,14 +700,23 @@ typedef struct SortGroupClause
  * RowMarkClause -
  *	   representation of FOR UPDATE/SHARE clauses
  *
- * We create a separate RowMarkClause node for each target relation
+ * We create a separate RowMarkClause node for each target relation.  In the
+ * output of the parser and rewriter, all RowMarkClauses have rti == prti and
+ * isParent == false.  When the planner discovers that a target relation
+ * is the root of an inheritance tree, it sets isParent true, and adds an
+ * additional RowMarkClause to the list for each child relation (including
+ * the target rel itself in its role as a child).  The child entries have
+ * rti == child rel's RT index, prti == parent's RT index, and can therefore
+ * be recognized as children by the fact that prti != rti.
  */
 typedef struct RowMarkClause
 {
 	NodeTag		type;
 	Index		rti;			/* range table index of target relation */
+	Index		prti;			/* range table index of parent relation */
 	bool		forUpdate;		/* true = FOR UPDATE, false = FOR SHARE */
 	bool		noWait;			/* NOWAIT option */
+	bool		isParent;		/* set by planner when expanding inheritance */
 } RowMarkClause;
 
 /*