Some infrastructure changes for the upcoming auto-explain contrib module:

* Refactor explain.c slightly to export a convenient-to-use subroutine
for printing EXPLAIN results.

* Provide hooks for plugins to get control at ExecutorStart and ExecutorEnd
as well as ExecutorRun.

* Add some minimal support for tracking the total runtime of ExecutorRun.
This code won't actually do anything unless a plugin prods it to.

* Change the API of the DefineCustomXXXVariable functions to allow nonzero
"flags" to be specified for a custom GUC variable.  While at it, also make
the "bootstrap" default value for custom GUCs be explicitly specified as a
parameter to these functions.  This is to eliminate confusion over where the
default comes from, as has been expressed in the past by some users of the
custom-variable facility.

* Refactor GUC code a bit to ensure that a custom variable gets initialized to
something valid (like its default value) even if the placeholder value was
invalid.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index c13f0cda7e7..f382c737214 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/pquery.c,v 1.124 2008/08/01 13:16:09 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/pquery.c,v 1.125 2008/11/19 01:10:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -82,6 +82,7 @@ CreateQueryDesc(PlannedStmt *plannedstmt,
 	qd->tupDesc = NULL;
 	qd->estate = NULL;
 	qd->planstate = NULL;
+	qd->totaltime = NULL;
 
 	return qd;
 }
@@ -110,6 +111,7 @@ CreateUtilityQueryDesc(Node *utilitystmt,
 	qd->tupDesc = NULL;
 	qd->estate = NULL;
 	qd->planstate = NULL;
+	qd->totaltime = NULL;
 
 	return qd;
 }