From 6244c2dfff6fa1b98fc8f13e59f656a20fad3564 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 9 Jul 2007 16:13:57 +0000
Subject: [PATCH] Fix stddev_pop(numeric) and var_pop(numeric), which were
incorrectly producing the same outputs as stddev_samp() and var_samp()
respectively.
---
src/backend/utils/adt/numeric.c | 7 +++++--
src/test/regress/expected/aggregates.out | 4 ++--
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 02523b8a5fc..e40e0470fb7 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -14,7 +14,7 @@
* Copyright (c) 1998-2007, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.105 2007/06/15 20:56:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.106 2007/07/09 16:13:57 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -2435,7 +2435,10 @@ numeric_stddev_internal(ArrayType *transarray,
}
else
{
- mul_var(&vN, &vNminus1, &vNminus1, 0); /* N * (N - 1) */
+ if (sample)
+ mul_var(&vN, &vNminus1, &vNminus1, 0); /* N * (N - 1) */
+ else
+ mul_var(&vN, &vN, &vNminus1, 0); /* N * N */
rscale = select_div_scale(&vsumX2, &vNminus1);
div_var(&vsumX2, &vNminus1, &vsumX, rscale, true); /* variance */
if (!variance)
diff --git a/src/test/regress/expected/aggregates.out b/src/test/regress/expected/aggregates.out
index 34b720f0f43..74635479e48 100644
--- a/src/test/regress/expected/aggregates.out
+++ b/src/test/regress/expected/aggregates.out
@@ -102,7 +102,7 @@ SELECT var_samp(b) FROM aggtest;
SELECT stddev_pop(b::numeric) FROM aggtest;
stddev_pop
------------------
- 151.389361431288
+ 131.107032862199
(1 row)
SELECT stddev_samp(b::numeric) FROM aggtest;
@@ -114,7 +114,7 @@ SELECT stddev_samp(b::numeric) FROM aggtest;
SELECT var_pop(b::numeric) FROM aggtest;
var_pop
--------------------
- 22918.738754573025
+ 17189.054065929769
(1 row)
SELECT var_samp(b::numeric) FROM aggtest;
--
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