Add missing optimizer hooks for function cost and number of rows.

Closely follow design of other optimizer hooks: if hook exists
retrieve value from plugin; if still not set then get from cache.

1 files changed, 16 insertions, 1 deletions

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 63dde8f9cb9..891abf422bc 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/lsyscache.c,v 1.168 2010/02/26 02:01:11 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/lsyscache.c,v 1.169 2010/04/23 22:23:39 sriggs Exp $
  *
  * NOTES
  *	  Eventually, the index information should go through here, too.
@@ -38,6 +38,9 @@
 /* Hook for plugins to get control in get_attavgwidth() */
 get_attavgwidth_hook_type get_attavgwidth_hook = NULL;
 
+/* Hook for plugins to get control in get_func_cost and get_func_rows */
+get_func_cost_hook_type get_func_cost_hook = NULL;
+get_func_rows_hook_type get_func_rows_hook = NULL;
 
 /*				---------- AMOP CACHES ----------						 */
 
@@ -1409,6 +1412,12 @@ get_func_cost(Oid funcid)
 	HeapTuple	tp;
 	float4		result;
 
+	if (get_func_cost_hook)
+	{
+		result = (*get_func_cost_hook) (funcid);
+		if (result > (float4) 0)
+			return result;
+	}
 	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
 	if (!HeapTupleIsValid(tp))
 		elog(ERROR, "cache lookup failed for function %u", funcid);
@@ -1428,6 +1437,12 @@ get_func_rows(Oid funcid)
 	HeapTuple	tp;
 	float4		result;
 
+	if (get_func_rows_hook)
+	{
+		result = (*get_func_rows_hook) (funcid);
+		if (result > (float4) 0)
+			return result;
+	}
 	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
 	if (!HeapTupleIsValid(tp))
 		elog(ERROR, "cache lookup failed for function %u", funcid);