Re: Use merge-based matching for MCVs in eqjoinsel
Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
From: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
To: David Geier <geidav.pg@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2025-09-08T10:45:06Z
Lists: pgsql-hackers
On 08.09.2025 13:35, Ilia Evdokimov wrote: > Based on these results, I’d prefer the hash lookup implementation, so > I think it makes sense to improve your patch further and bring it into > good shape. Shall I take care of that, or would you prefer to do it > yourself? I realized I mistakenly copied the wrong results for the hash-map version in my previous draft. Sorry about that. Here are the correct benchmark results: Merge default_statistics_target | Planner Speedup (×) | Planner Before (ms) | Planner After (ms) -------------------------------------------------------------------------------- 100 | 1.00 | 1892.627 | 1898.622 1000 | 1.12 | 2286.922 | 2033.553 2500 | 1.92 | 4647.167 | 2423.552 5000 | 5.94 | 17964.779 | 3025.739 7500 | 10.48 | 38622.443 | 3684.262 10000 | 16.72 | 69538.085 | 4159.418 Hash-Map default_statistics_target | Planner Speedup (×) | Planner Before (ms) | Planner After (ms) -------------------------------------------------------------------------------- 100 | 1.00 | 1892.627 | 1886.969 1000 | 1.09 | 2286.922 | 2100.099 2500 | 1.94 | 4647.167 | 2400.711 5000 | 6.15 | 17964.779 | 2919.914 7500 | 10.58 | 38622.443 | 3650.375 10000 | 16.33 | 69538.085 | 4257.864 -- Best regards, Ilia Evdokimov, Tantor Labs LLC, https://tantorlabs.com