try it with a table with 650K rows... On Tue, 2007-06-12 at 15:32 +0200, Christo Du Preez wrote: > Good day, > > I have noticed that my server never uses indexing. No matter what I do. > > As an example I took a table with about 650 rows, having a parentid > field with an index on parentid. > > EXPLAIN ANALYZE > SELECT * > FROM layertype > where parentid = 300; > > On my laptop the explain analyze looks like this: > > "Index Scan using fki_layertype_parentid on layertype (cost=0.00..8.27 > rows=1 width=109)" > " Index Cond: (parentid = 300)" > > and on the problem server: > > "Seq Scan on layertype (cost=0.00..20.39 rows=655 width=110)" > " Filter: (parentid = 300)" > > ......... > > I have dropped the index, recreated it, vacuumed the table, just about > everything I could think of, And there is just no way I can get the > query planner to use the index. > > PostgreSQL 8.2.3 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 > 20061115 (prerelease) (SUSE Linux) > POSTGIS="1.2.1" GEOS="3.0.0rc4-CAPI-1.3.3" PROJ="Rel. 4.5.0, 22 Oct > 2006" USE_STATS > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq
