On 2/28/24 15:38, Melanie Plageman wrote: > On Wed, Feb 28, 2024 at 8:22 AM Tomas Vondra > <tomas.von...@enterprisedb.com> wrote: >> >> Hi, >> >> I haven't looked at the code very closely yet, but I decided to do some >> basic benchmarks to see if/how this refactoring affects behavior. >> >> Attached is a simple .sh script that >> >> 1) creates a table with one of a couple basic data distributions >> (uniform, linear, ...), with an index on top >> >> 2) runs a simple query with a where condition matching a known fraction >> of the table (0 - 100%), and measures duration >> >> 3) the query is forced to use bitmapscan by disabling other options >> >> 4) there's a couple parameters the script varies (work_mem, parallel >> workers, ...), the script drops caches etc. >> >> 5) I only have results for table with 1M rows, which is ~320MB, so not >> huge. I'm running this for larger data set, but that will take time. >> >> >> I did this on my two "usual" machines - i5 and xeon. Both have flash >> storage, although i5 is SATA and xeon has NVMe. I won't share the raw >> results, because the CSV is like 5MB - ping me off-list if you need the >> file, ofc. > > I haven't looked at your results in detail yet. I plan to dig into > this more later today. But, I was wondering if it was easy for you to > run the shorter tests on just the commits before the last > https://github.com/melanieplageman/postgres/tree/bhs_pgsr > i.e. patches 0001-0013. Patch 0014 implements the streaming read user > and removes all of the existing prefetch code. I would be interested > to know if the behavior with just the preliminary refactoring differs > at all. >
Sure, I can do that. It'll take a couple hours to get the results, I'll share them when I have them. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
