Tweak indexscan machinery to avoid taking an AccessShareLock on an index

if we already have a stronger lock due to the index's table being the
update target table of the query.  Same optimization I applied earlier
at the table level.  There doesn't seem to be much interest in the more
radical idea of not locking indexes at all, so do what we can ...

1 files changed, 3 insertions, 1 deletions

diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index f1d4e37c419..facb10a2e25 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.122 2005/12/02 20:03:42 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.123 2005/12/03 05:51:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -230,6 +230,8 @@ extern void ExecAssignScanType(ScanState *scanstate,
 				   TupleDesc tupDesc, bool shouldFree);
 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 
+extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
+
 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid);
 extern void ExecCloseScanRelation(Relation scanrel);