Cache fmgr lookup data for index's getnext() function in IndexScanDesc,

so that the fmgr lookup only has to happen once per index scan and not
once per tuple.  Seems to save 5% or so of CPU time for an indexscan.

diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 103f02e..1bd02f8 100644 (file)
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.23 2000/01/26 05:55:57 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.24 2000/03/14 23:52:01 tgl Exp $
  *
  * NOTES
  *       many of the old access method routines have been turned into
@@ -114,6 +114,9 @@ RelationGetIndexScan(Relation relation,
        ItemPointerSetInvalid(&scan->currentMarkData);
        ItemPointerSetInvalid(&scan->nextMarkData);
 
+       /* mark cached function lookup data invalid; it will be set on first use */
+       scan->fn_getnext.fn_oid = InvalidOid;
+
        if (numberOfKeys > 0)
                scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * numberOfKeys);
        else

diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index f4f0d25..2335693 100644 (file)
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/access/index/indexam.c,v 1.40 2000/01/26 05:55:57 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/access/index/indexam.c,v 1.41 2000/03/14 23:52:01 tgl Exp $
  *
  * INTERFACE ROUTINES
  *             index_open              - open an index relation by relationId
@@ -329,17 +329,28 @@ RetrieveIndexResult
 index_getnext(IndexScanDesc scan,
                          ScanDirection direction)
 {
-       RegProcedure procedure;
        RetrieveIndexResult result;
 
        SCAN_CHECKS;
-       GET_SCAN_PROCEDURE(getnext, amgettuple);
+
+       /* ----------------
+        *      Look up the access procedure only once per scan.
+        * ----------------
+        */
+       if (scan->fn_getnext.fn_oid == InvalidOid)
+       {
+               RegProcedure procedure;
+
+               GET_SCAN_PROCEDURE(getnext, amgettuple);
+               fmgr_info(procedure, &scan->fn_getnext);
+       }
 
        /* ----------------
         *      have the am's gettuple proc do all the work.
         * ----------------
         */
-       result = (RetrieveIndexResult) fmgr(procedure, scan, direction);
+       result = (RetrieveIndexResult)
+               (*fmgr_faddr(&scan->fn_getnext)) (scan, direction);
 
        return result;
 }

diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h
index c3101bd..19e4e28 100644 (file)
--- a/src/include/access/relscan.h
+++ b/src/include/access/relscan.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: relscan.h,v 1.18 2000/01/26 05:57:51 momjian Exp $
+ * $Id: relscan.h,v 1.19 2000/03/14 23:52:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -54,6 +54,7 @@ typedef struct IndexScanDescData
        bool            scanFromEnd;    /* restart scan at end? */
        uint16          numberOfKeys;   /* number of key attributes */
        ScanKey         keyData;                /* key descriptor */
+       FmgrInfo        fn_getnext;             /* cached lookup info for am's getnext fn */
 } IndexScanDescData;
 
 typedef IndexScanDescData *IndexScanDesc;