Actually the first time this happened was with 8.3+1.3.3, at that time debian still didn't have the postgis package for postgres 8.3 so I compiled postgis myself. Having that slow performance with that query I figured I had done something wrong with the compilation, so I stayed with 8.2+1.3.2, this week I tried again, given that debian testing already had postgis packages, but the speed was the same.
Paul Ramsey wrote: > That's deeply odd, and worth investigating. Can you try 8.3+1.3.3, so > we can eliminate the PostGIS version as a variable first? Then I'll > see if I can duplicate the result on my system. > > P. > > On Sat, Sep 27, 2008 at 12:59 PM, David Vaz <[EMAIL PROTECTED]> wrote: > >> Hi, >> >> I am a debian user, several months ago debian testing introduced >> postgresql-8.3, and later postgis 1.3 for postgresql-8.3. The problem I >> am facing is that length_spheroid is much slower in postgres-8.3 from >> under 1s to about 60s (See Bellow). I have google-it without any luck. >> Does anyone have any idea on why this happens? >> >> Both databases are equal, tested in same machine, with different >> installations to avoid software versions conflicts. >> >> FIRST: >> postgresql-8.2 (version 8.2.7-2+b1) with postgis (version 1.3.2-1) >> >> EXPLAIN ANALYSE select length_spheroid(geom,'SPHEROID["WGS >> 84",6378137,298.257223563]') FROM test order by id limit 100; >> >> QUERY >> PLAN >> ------------------------------------------------------------------------------------------------------------------------------------------------------- >> Limit (cost=0.00..17.44 rows=100 width=26054) (actual >> time=1.852..588.394 rows=100 loops=1) >> -> Index Scan using test_pkey on test (cost=0.00..2268.52 >> rows=13010 width=26054) (actual time=1.850..588.298 rows=100 loops=1) >> Total runtime: 588.495 ms >> (3 rows) >> >> SECOND: >> postgresql-8.3 (version 8.3.3-1) with postgis (version 1.3.3-3) >> >> EXPLAIN ANALYSE select length_spheroid(geom,'SPHEROID["WGS >> 84",6378137,298.257223563]') FROM test order by id limit 100; >> >> QUERY >> PLAN >> >> ------------------------------------------------------------------------------------------------------------------------------------------------------------ >> Limit (cost=0.00..8.74 rows=100 width=104429) (actual >> time=182.734..59741.720 rows=100 loops=1) >> -> Index Scan using test_pkey on test (cost=0.00..1137.11 >> rows=13010 width=104429) (actual time=182.732..59741.572 rows=100 loops=1) >> Total runtime: 59741.897 ms >> (3 rows) >> >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> >> > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
