Thanks for the tip for the index on multiple columns ! (I never do inserts on this table so insert time doesn't matter)
Mys posgresql version is : PostgreSQL 7.2.1 Here are the results of the EXPLAIN ANALYZE you asked me to execute. explain analyse select cp from base_aveugle where cp='69740' and effectif between 1 and 50; NOTICE: QUERY PLAN: Index Scan using base_aveugle_cp_eff on base_aveugle (cost=0.00..508.69 rows=126 width=32) (actual time=0.27..11.56 rows=398 loops=1) Total runtime: 11.77 msec EXPLAIN explain analyse select cp from base_aveugle where cp like '69%' and effectif between 1 and 50 and naf like '24%' or naf like '25%'; NOTICE: QUERY PLAN: Index Scan using base_aveugle_cp_eff_naf, base_aveugle_naf on base_aveugle (cost=0.00..100001.89 rows=25245 width=32) (actual time=4.40..353.69 rows=6905 loops=1) Total runtime: 355.82 msec EXPLAIN thx ;) --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.737 / Virus Database: 491 - Release Date: 11/08/2004 ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster