Re: Add a greedy join search algorithm to handle large join problems - Mailing list pgsql-hackers

Hi Tomas,

Thank you for the clarification. You’re right that the synthetic test doesn’t strongly constrain join order and, with the default  join_collapse_limit ,  the DP comparison was limited.

I’m now preparing follow-up tests using selected JOB queries and adjusted planner settings to provide a fair and more realistic comparison. I’ll share the results soon.

         Following up on my previous message, I ran some additional tests using a few selected JOB queries with DP, GEQO and GOO under the same planner settings.

        Configuration used:

• join_collapse_limit = 100
• from_collapse_limit = 100
• max_parallel_workers_per_gather = 0
• PostgreSQL 19devel with the GOO v5 patch

Query   DP Plan(ms)   DP Exec(ms)   GEQO Plan(ms)   GEQO Exec(ms)   GOO Plan(ms)   GOO Exec(ms)
-----------------------------------------------------------------------------------------------
12b     4.97          0.16          54.57           0.11            4.18           0.12
24a     88.94         0.21          67.10           0.12            6.26           0.12
26b     68.58         0.20          44.44           0.10            3.90           0.07
29a     1903.9        0.24          14.73           0.22            25.47          0.26
33c     163.25        0.28          52.93           0.18            3.98           0.07

      Regards,
     Lakshmi