Wow, nice! Can you tell us: - how big is the table - cardinality of the column - how big is the index in each case - how much memory on the machine - query and explain analyze
Thanks! - Luke Msg is shrt cuz m on ma treo -----Original Message----- From: Grzegorz Jaskiewicz [mailto:[EMAIL PROTECTED] Sent: Saturday, March 17, 2007 05:16 PM Eastern Standard Time To: Joshua D.Drake Cc: Heikki Linnakangas; PostgreSQL-development Hackers Subject: Re: [HACKERS] [PATCHES] Bitmapscan changes This is on dual ultra 2 sparc. with ultrawide 320 scsi drives. 512MB ram. I had to drop size of DB, because the DB drive is 4GB (I do welecome bigger drives as donation, if someone asks - UWscsi 320). here are my results. With only 4.2 patch (no maintain cluster order v5 patch). If the v5 patch was needed, please tell me - I am going rerun it with. hope it is usefull. Repeat 3 times to ensure repeatable results. Timing is on. select_with_normal_index -------------------------- 100000 (1 row) Time: 1727891.334 ms select_with_normal_index -------------------------- 100000 (1 row) Time: 1325561.252 ms select_with_normal_index -------------------------- 100000 (1 row) Time: 1348530.100 ms Timing is off. And now run the same tests with clustered index Timing is on. select_with_clustered_index ----------------------------- 100000 (1 row) Time: 870246.856 ms select_with_clustered_index ----------------------------- 100000 (1 row) Time: 477089.456 ms select_with_clustered_index ----------------------------- 100000 (1 row) Time: 381880.965 ms Timing is off. ---------------------------(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
