Re: Defaulting to jit=on/off for v11

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org
Date: 2018-09-14T22:32:03Z
Lists: pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> I can see basically three sensible routes to go for v11 (before we
> improve further):

> 1) Leave it enabled, as currently.

> 2) Disable it by default in v11, leave it enabled in master.

> 3) Increase the costs substantially, so it triggers in far fewer
>    cases. Those would be too high for cases that want to benefit fully,
>    but would reduce the risk - although it also probably makes it
>    harder to easily hit problematic cases.

I'd go with #2, personally.  It does seem that the costing needs work,
but it's not clear to me that we know what to change, so it's kinda
late to propose #3 for v11.

			regards, tom lane


Commits

  1. In v11, disable JIT by default (it's still enabled by default in HEAD).