Am Mittwoch, 6. Oktober 2004 12:19 schrieb Pierre-Frédéric Caillaud: > You could try : > > explain analyze select "land" from "customer_dim" group by "land"; > It will be a lot faster but I can't make it use the index on my machine... this already speeds up my queries to about 1/4th of the time, which is about the range of mysql and oracle. > > Example : > > [..] > > Hum hum ! Again, a lot better ! > Index scan backwards seems a lot faster than index scan forwards. Why, I > don't know, but here you go from 15 seconds to 14 milliseconds... thanks for this very extensive answer, it helped me a lot. > > I don't know WHY (oh why) postgres does not use this kind of strategy > when distinct'ing an indexed field... Anybody got an idea ? That's the big question I still would like to see answered too. Can anyone tell us?
TiA -- Ole Langbehn ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly