Re: Unnecessary buffer usage with multicolumn index, row comparison, and equility constraint

2024-05-10 Thread Tom Lane
Ron Johnson writes: > On Fri, May 10, 2024 at 11:28 PM WU Yan <4wu...@gmail.com> wrote: >> Simple query that uses the multicolumn index. >> postgres=# explain (analyze, buffers) select * from t where row(a, b) > >> row(123450, 123450) and a = 0 order by a, b; > Out of curiosity, why "where

Re: Unnecessary buffer usage with multicolumn index, row comparison, and equility constraint

2024-05-10 Thread Ron Johnson
On Fri, May 10, 2024 at 11:28 PM WU Yan <4wu...@gmail.com> wrote: > Hi everyone, first time here. Please kindly let me know if this is not the > right place to ask. > > I notice a simple query can read a lot of buffer blocks in a meaningless > way, when > 1. there is an index scan on a

Unnecessary buffer usage with multicolumn index, row comparison, and equility constraint

2024-05-10 Thread WU Yan
Hi everyone, first time here. Please kindly let me know if this is not the right place to ask. I notice a simple query can read a lot of buffer blocks in a meaningless way, when 1. there is an index scan on a multicolumn index 2. there is row constructor comparison in the Index Cond 3. there is