You didn't mention version, but 8.1.x has bitmap index scans that might greatly speed this up...
On Sat, Apr 22, 2006 at 02:34:13PM -0700, [EMAIL PROTECTED] wrote: > Hi List > I have maybe an easy question but i do not find an answer, i have this > SQL query: > > SELECT geom,group,production_facs FROM south_america > WHERE municipio = '' > OR municipio = 'ACRE' > OR municipio = 'ADJUNTAS' > OR municipio = 'AGUADA' > > The performance of this query is quite worse as longer it gets, its > possible that this query gets over 20 to 30 OR comparisons, but then > the performance is really worse, is it possible to speed it up? > Thanks > Clemens > > > ---------------------------(end of broadcast)--------------------------- > TIP 5: don't forget to increase your free space map settings > -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
