Re: Use merge-based matching for MCVs in eqjoinsel

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