Re: Query is over 2x slower with jit=on - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Query is over 2x slower with jit=on
Date
Msg-id 20180822185205.dtfe722isnkdlfgg@alap3.anarazel.de
Whole thread Raw
In response to Sv: Re: Query is over 2x slower with jit=on  (Andreas Joseph Krogh <andreas@visena.com>)
Responses Re: Query is over 2x slower with jit=on
List pgsql-hackers
On 2018-08-22 19:51:12 +0200, Andreas Joseph Krogh wrote:
> I thought JITing of prepared queries happended once (in "prepare")

No, it happens when the first JITed function is executed.


>  so it didn't have to do the JITing every time the query is
> executed. Isn't the previously generated bytecode usable for
> subsequent queries?

No, not currently. There's some reasons preventing that (primarily that
we currently rely on addresses of certain things not to change during
execution). There's ongoing work to change that, but that's certainly
not going to be ready for v11.

Greetings,

Andres Freund


pgsql-hackers by date:

Previous
From: Pierre Ducroquet
Date:
Subject: Re: Query is over 2x slower with jit=on
Next
From: Andreas Joseph Krogh
Date:
Subject: Re: Query is over 2x slower with jit=on