You make some unsubstantiated claims here. I assure you that it isn't as simple as you claim. And what Postgres does here is (mostly) the right thing, you can't do much better. You simply can't decide what plan you need to use based on the query and its parameters alone, unless you already cached that plan for those parameters (and even in that case you need to watch out for possible dramatic changes in statistics). Prepared statements != cached execution plans.

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SigmundA 2 hours ago | parent [-]

Ah yes so Microsoft and Oracle do these things for no good reason, you are the one making unsubstantiated claims such as "you can't do much better". And "You simply can't decide what plan you need to use based on the query and its parameters alone" which is mostly what those systems do (along with statistics). If you bothered to read what I linked you could see exactly how they are doing it.

I never said it was simple, in fact I said how primitive PG is compared to the "big boys" because they put huge effort into making their systems fast back in the TPS wars of the early 2000's on much slower hardware.

>Prepared statements != cached execution plans

Thats exactly what a prepared statement is:

https://en.wikipedia.org/wiki/Prepared_statement

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vladich an hour ago | parent [-]

There are reasons for that, it's useful in a very narrow set of situations. Postgres cached plans exist for the same reason. If you're claiming Oracle and MSSQL do _much_ better in this area - that's what I call unsubstantiated. From what you write further it's pretty clear you don't have a lot of understanding what happens under the hood. And no, prepared statements are not what you read in Wikipedia. Not in all databases anyway. Go read it somewhere else.

	▲	SigmundA 33 minutes ago \| parent [-]
		>There are reasons for that, it's useful in a very narrow set of situations. So narrow its enabled by default for all statements from the "big boy" commercial RDBMS's... https://www.ibm.com/docs/en/i/7.4.0?topic=overview-plan-cach... https://docs.oracle.com/en/database/oracle/oracle-database/1... https://learn.microsoft.com/en-us/sql/relational-databases/p... https://help.sap.com/docs/SAP_HANA_PLATFORM/6b94445c94ae495c... >Postgres cached plans exist for the same reason. Postgresql doesn't cache plans unless the client explicitly sends commands to do so. Applications cannot take advantage of this unless they keep connections open and reuse them in a pool and they must mange this themselves. The plan has to be planned for every separate connection/process rather than a single cached planed increasing server memory costs which are plan cache size X number of connections. It has no "reason" to cache plans the client must do this using its "reasons". >If you're claiming Oracle and MSSQL do _much_ better in this area - that's what I call unsubstantiated. You are making all sorts of claims without nary a link to back it up. Are you suggestion PG does better than MSSQL, Oracle and DB2 in planning while be constrained to replan on every single statement? The PG planner is specifically kept simple so that it is fast at its job, not thorough or it would adversely effect execution time more than it already does, this is well documented and always a concern when new features are proposed for it. >From what you write further it's pretty clear you don't have a lot of understanding what happens under the hood. Sticks and stones, is that all you have how about something substantial. > And no, prepared statements are not what you read in Wikipedia. Not in all databases anyway. Ok Mr. Unsubstantiated are we talking about PG or not? What does one use prepared statements for in PG hmmm, you know the thing you call the PG plan cache? How about something besides your claim that prepared statements aren't not in fact plan caches? Are you talking about complete different DB systems? How about you substantiate that?