How Postgres chooses which index to use for a query

Re:How Postgres chooses which index to use for a query by alyandon on Thursday April 21, 2022 @06:58PM (#31116195)

There is no optimizer that is capable of getting the correct result 100% of the time. Even Oracle with decades of costly engineering behind it requires query tuning (either via explicit hints on the client side sql or via server side plan tuning) at any reasonably large scale.

I like Postgresql and use it when I can and I respect the Postgreql core dev team's adherence to principles but in this particular case I believe they are just inventing arguments to justify their unreasonable stance against allowing query hinting.

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Re:How Postgres chooses which index to use for a query by _jal on Thursday April 21, 2022 @07:34PM (#31116490)

So "most of the time" means "100% of the time" where you live?

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Re:How Postgres chooses which index to use for a query by stormbrew on Thursday April 21, 2022 @10:31PM (#31117588)

I mean, I think this is just one of those things where it only matters rarely, but when it does it matters a lot.

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Re:How Postgres chooses which index to use for a query by staticassertion on Thursday April 21, 2022 @11:22PM (#31117837)

Maybe postgres isn't the right solution in those cases. If you need tight control over how your queries are executing you may not want an rdbms.

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Re:How Postgres chooses which index to use for a query by stormbrew on Friday April 22, 2022 @04:32AM (#31119433)

I don't think choices of things like this ever really come down to one thing like that. Not using an RDBMS might mean having to build a whole bunch of features you wouldn't otherwise have to.

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Re:How Postgres chooses which index to use for a query by kadoban on Friday April 22, 2022 @12:46AM (#31118310)

That's possible I guess, but at least some other relational dbs do allow that control, so it's not like it's impossible.

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