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 103f02ecc0c9e32b7ef99084059354ed61621a8a..1bd02f839ad42236df3bdd5e1966495c7cc470f8 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 f4f0d25768b3633ab88077a4eec943c7fcc7f820..2335693119829d6fc289c165b1b57b41361f6f72 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 c3101bd92f66dc678bb5901e83cafbd0f198684b..19e4e28631d60328427407bf81429ca95d258f9f 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;