Avoid overflow in cost_sort when work_mem exceeds 1Gb.

diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 2b6dc27973a3ad7ec0bafd12e444341a92f6bca9..c67398d5b0d95fc959cb8e8a801d609e5c6d0e04 100644 (file)
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -49,7 +49,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.134 2004/08/29 05:06:43 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.135 2004/10/23 00:05:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -566,7 +566,7 @@ cost_sort(Path *path, Query *root,
        if (nbytes > work_mem_bytes)
        {
                double          npages = ceil(nbytes / BLCKSZ);
-               double          nruns = nbytes / (work_mem_bytes * 2);
+               double          nruns = (nbytes / work_mem_bytes) * 0.5;
                double          log_runs = ceil(LOG6(nruns));
                double          npageaccesses;