What is the data type for "signum" ??? "David Rysdam" <drysdam@xxxxxxxxxx> wrote in message news:437CA40A.8020507@xxxxxxxxxxxxx > I'm porting an application from Sybase and I've noticed that similar > application functions take 2 to 3 times longer on postgres than they used > to on the same machine running under Sybase. I've tried changing various > "performance tuning" parameters, such as shared_buffers, > effective_cache_size, etc but there's little or no effect. I'm beginning > to think there's a deeper root cause to the slowness. > > Right now, I'm working on a test case that involves a table with ~360k > rows called "nb.sigs". My sample query is: > > select * from nb.sigs where signum > 250000 > > With no index, explain says this query costs 11341. After CREATE INDEX on > the signum field, along with an ANALYZE for nb.sigs, the query costs 3456 > and takes around 4 seconds to return the first row. This seems extremely > slow to me, but I can't figure out what I might be doing wrong. Any > ideas? > > (If necessary, I can write an entire script that creates and populates a > table and then give my performance on that sample for someone else to > check against.) > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend > ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly
