From: Sandro Santilli <strk@keybit.net>
Date: Tue, 9 Apr 2013 22:43:27 +0000 (+0000)
Subject: Fix access to random memory during ANALYZE
X-Git-Tag: 2.1.0beta2~111
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c0631ec024cc4b1093d9c39141505ee8f1ec1b65;p=postgis

Fix access to random memory during ANALYZE

The bug was introduced with previous commit, see #2269

As part of this fix, the stawidth field of pg_statistics is
changed to represent the average _compressed_ size rather
than the average _uncompressed_ size of non-null geometry
values. This may have some consequence on the planner (not
known at time of commit).

git-svn-id: http://svn.osgeo.org/postgis/trunk@11276 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/postgis/geometry_estimate.c b/postgis/geometry_estimate.c
index c61a68ffb..94a5a2593 100644
--- a/postgis/geometry_estimate.c
+++ b/postgis/geometry_estimate.c
@@ -872,7 +872,6 @@ compute_geometry_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc,
 	for (i=0; i<samplerows; i++)
 	{
 		Datum datum;
-		GSERIALIZED *geom;
 		GBOX box;
 
 		datum = fetchfunc(stats, i, &isnull);
@@ -886,6 +885,9 @@ compute_geometry_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc,
 			continue;
 		}
 
+		/** NOTE: we use the toasted width for stawidth */
+		total_width += VARSIZE_ANY(DatumGetPointer(datum));
+
 		if ( LW_FAILURE == gserialized_datum_get_gbox_p(datum, &box) )
 		{
 			/* Skip empty geometry */
@@ -934,8 +936,6 @@ compute_geometry_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc,
 			                                  box.ymin);
 		}
 
-		/** TODO: ask if we need geom or bvol size for stawidth */
-		total_width += VARSIZE(geom);
 		total_boxes_area += (box.xmax-box.xmin)*(box.ymax-box.ymin);
 
 		/*