On Tue, Nov 22, 2022 at 11:44 PM David Rowley <dgrowle...@gmail.com> wrote:
> On Wed, 23 Nov 2022 at 20:29, sirisha chamarthi > <sirichamarth...@gmail.com> wrote: > > I ran your test1 exactly like your setup except the row count is 3000000 > (with 13275 blocks). Shared_buffers is 128MB and the hardware configuration > details at the bottom of the mail. It appears Master + 0001 + 0005 > regressed compared to master slightly . > > Thank you for running these tests. > > Can you share if the plans used for these queries was a parallel plan? > I had set max_parallel_workers_per_gather to 0 to remove the > additional variability from parallel query. > > Also, 13275 blocks is 104MBs, does EXPLAIN (ANALYZE, BUFFERS) indicate > that all pages were in shared buffers? I used pg_prewarm() to ensure > they were so that the runs were consistent. > I reran the test with setting max_parallel_workers_per_gather = 0 and with pg_prewarm. Appears I missed some step while testing on the master, thanks for sharing the details. New numbers show master has higher latency than *Master + 0001 + 0005*. *Master* Before vacuum: latency average = 452.881 ms After vacuum: latency average = 393.880 ms *Master + 0001 + 0005* Before vacuum: latency average = 441.832 ms After vacuum: latency average = 369.591 ms
