[PERFORM] DISTINCT and GROUP BY: possible performance enhancement?

2004-11-07 Thread Ang Chin Han
Is SELECT DISTINCT foo, bar FROM baz; equivalent to SELECT foo, bar from baz GROUP BY foo, bar; ? In the former case, pgsql = 7.4 does not use HashAgg, but uses it for the latter case. In many circumstances, esp. for large amount of data in the table baz, the second case is an order of a

Re: [PERFORM] postgresql amd-64

2004-11-07 Thread Iain
I'm hoping I'll have the opportunity to build a similar machine soon and am wondering about the choice of 64 bit distributions. Gentoo is obviously a possibility but I'm also condsidering Debian. There is also a 64 compile of redhat sources somewhere around, but I can't remember what they call

Re: [PERFORM] Restricting Postgres

2004-11-07 Thread Matthew Nuzum
Matt - Very interesting information about squid effectiveness, thanks. Martin, You mean your site had no images? No CSS files? No JavaScript files? Nearly everything is dynamic? I've found that our CMS spends more time sending a 23KB image to a dial up user than it does generating and serving

Re: [PERFORM] poor performance in migrated database

2004-11-07 Thread Troels Arvin
On Sat, 06 Nov 2004 11:52:15 -0800, Carlos Lopez wrote: I have migrated a database from MS SQL to a postgresSQL database, but when running it, the results are very slow (and unusable) which is the only reason we don't entirely move to postgresSQL. Have you run ANALYZE lately? (See manual.)