BUG #4567: Clustering on GIST INDEX clobbers records in table intermittently
The following bug has been logged online:
Bug reference: 4567
Logged by: Regina Obe
Email address: robe.dnd@cityofboston.gov
PostgreSQL version: 8.3.5
Operating system: Numerous
Description: Clustering on GIST INDEX clobbers records in table
intermittently
Details:
This doesn't always happen to me but does intermittently, and for others it
happens all the time. Several of us have tried to recreate the issue. For
me it happens once in a while on EL 4, 8.3.5 install. We have confirmed it
happens on all GIST type indexes.
We have not noticed this problem prior to 8.3.5 -- checkout this thread for
details.
http://postgis.refractions.net/pipermail/postgis-devel/2008-December/004284.
html
http://postgis.refractions.net/pipermail/postgis-devel/2008-December/004275.
html
http://postgis.refractions.net/pipermail/postgis-devel/2008-December/004283.
html
To recreate:
1) restart your postgresql service
2) run below
test=# create temp table tmp as select st_makepoint(random(), random()) as
the_geom from generate_series(1, 10000);
SELECT
test=# create index tmp_geom_idx on tmp using gist (the_geom);
CREATE INDEX
test=# analyze tmp;
ANALYZE
test=# select count(*) from tmp;
count
-------
10000
(1 row)
test=# cluster tmp using tmp_geom_idx;
CLUSTER
test=# analyze tmp;
ANALYZE
test=# select count(*) from tmp;
count
-------
0
(1 row)
Running the same exercise for me on 8.3.1 always seems to work correctly as
far as I can tell.
"Regina Obe" <robe.dnd@cityofboston.gov> writes:
Description: Clustering on GIST INDEX clobbers records in table
intermittently
This doesn't always happen to me but does intermittently, and for others it
happens all the time.
I wonder whether this is fixed by this recent patch:
http://archives.postgresql.org/pgsql-committers/2008-12/msg00053.php
The pre-patch behavior would've depended on the value of a
never-initialized struct field, so the erratic behavior is explained
by varying contents of memory. I'm unable to make it happen in an
assert-enabled build, but that's probably because the initial contents
of a palloc'd chunk are never zeroes in such a build.
regards, tom lane
"Regina Obe" <robe.dnd@cityofboston.gov> writes:
Description: Clustering on GIST INDEX clobbers records in table
intermittently
This doesn't always happen to me but does intermittently, and for others it
happens all the time.
I wonder whether this is fixed by this recent patch:
http://archives.postgresql.org/pgsql-committers/2008-12/msg00053.php
The pre-patch behavior would've depended on the value of a
never-initialized struct field, so the erratic behavior is explained
by varying contents of memory. I'm unable to make it happen in an
assert-enabled build, but that's probably because the initial contents
of a palloc'd chunk are never zeroes in such a build.
regards, tom lane
Tom,
Thanks for the quick response on this.
Paul,
You think by chance you can test out the patch since you can make this bug happen consistently on your build.
Thanks,
Regina
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Yes, that patch removes the bug.
P.
Show quoted text
On Sun, Dec 7, 2008 at 11:51 PM, Obe, Regina <robe.dnd@cityofboston.gov> wrote:
"Regina Obe" <robe.dnd@cityofboston.gov> writes:
Description: Clustering on GIST INDEX clobbers records in table
intermittentlyThis doesn't always happen to me but does intermittently, and for others
it
happens all the time.I wonder whether this is fixed by this recent patch:
http://archives.postgresql.org/pgsql-committers/2008-12/msg00053.phpThe pre-patch behavior would've depended on the value of a
never-initialized struct field, so the erratic behavior is explained
by varying contents of memory. I'm unable to make it happen in an
assert-enabled build, but that's probably because the initial contents
of a palloc'd chunk are never zeroes in such a build.regards, tom lane
Tom,
Thanks for the quick response on this.
Paul,
You think by chance you can test out the patch since you can make this bug
happen consistently on your build.Thanks,
Regina________________________________
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