[kevan]

Do any relational DBs let you lock statistics or the query planner directly? Something like how ML pipelines are split between training and inference phases. Let me train the optimizer on a representative load (prod replay or synthetic) and then lock the query planner for my production traffic. Still take advantage of the black magic but control it so query plans don't unexpectedly change.

[ako]

Problem with databases is that they have the tendency to grow over time, so the statistics change all the time, and thus the optimal query plan.

[iracic]

Yes, some are able to verify that execution plan already exists (saved in gather run or by explicit command) before replaning. Also you can group them with one label and activate only when needed.

I guess that there must be a good number of people who would use it in PostgreSQL. Anybody analyzed previous tries to implement it?

[protomyth]

Sybase 11 and 12 let you force a plan and declare what indexes to use including temp tables if they were declared in a stored procedure that was calling the stored procedure you used the indexes. The optimizer was not the best.

[daigoba66]

MSSQL mostly has this feature with Query Store.