Improve the plan cache invalidation mechanism to make it invalidate plans

when user-defined functions used in a plan are modified.  Also invalidate
plans when schemas, operators, or operator classes are modified; but for these
cases we just invalidate everything rather than tracking exact dependencies,
since these types of objects seldom change in a production database.

Tom Lane; loosely based on a patch by Martin Pihlak.

3 files changed, 27 insertions, 3 deletions

diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 7e3d67a241f..c02b4c17904 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.211 2008/08/30 01:39:14 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.212 2008/09/09 18:58:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -67,6 +67,8 @@ typedef enum NodeTag
 	T_Hash,
 	T_SetOp,
 	T_Limit,
+	/* this one isn't a subclass of Plan: */
+	T_PlanInvalItem,
 
 	/*
 	 * TAGS FOR PLAN STATE NODES (execnodes.h)
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index f0e0d08e03a..2f0ed9a5d79 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/plannodes.h,v 1.102 2008/08/07 19:35:02 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/plannodes.h,v 1.103 2008/09/09 18:58:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,6 +17,7 @@
 #include "access/sdir.h"
 #include "nodes/bitmapset.h"
 #include "nodes/primnodes.h"
+#include "storage/itemptr.h"
 
 
 /* ----------------------------------------------------------------
@@ -72,6 +73,8 @@ typedef struct PlannedStmt
 
 	List	   *relationOids;	/* OIDs of relations the plan depends on */
 
+	List	   *invalItems;		/* other dependencies, as PlanInvalItems */
+
 	int			nParamExec;		/* number of PARAM_EXEC Params used */
 } PlannedStmt;
 
@@ -559,4 +562,21 @@ typedef struct Limit
 	Node	   *limitCount;		/* COUNT parameter, or NULL if none */
 } Limit;
 
+
+/*
+ * Plan invalidation info
+ *
+ * We track the objects on which a PlannedStmt depends in two ways:
+ * relations are recorded as a simple list of OIDs, and everything else
+ * is represented as a list of PlanInvalItems.  A PlanInvalItem is designed
+ * to be used with the syscache invalidation mechanism, so it identifies a
+ * system catalog entry by cache ID and tuple TID.
+ */
+typedef struct PlanInvalItem
+{
+	NodeTag		type;
+	int			cacheId;		/* a syscache ID, see utils/syscache.h */
+	ItemPointerData tupleId;	/* TID of the object's catalog tuple */
+} PlanInvalItem;
+
 #endif   /* PLANNODES_H */
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 8fb6861e50c..c66bc05a749 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.158 2008/08/14 18:48:00 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.159 2008/09/09 18:58:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -74,6 +74,8 @@ typedef struct PlannerGlobal
 
 	List	   *relationOids;	/* OIDs of relations the plan depends on */
 
+	List	   *invalItems;		/* other dependencies, as PlanInvalItems */
+
 	bool		transientPlan;	/* redo plan when TransactionXmin changes? */
 } PlannerGlobal;