Re: PG 15 (and to a smaller degree 14) regression due to ExprEvalStep size

On Tue, Jun 21, 2022 at 05:41:07PM -0400, Andrew Dunstan wrote:
> On 2022-06-21 Tu 17:25, Andres Freund wrote:
>> On 2022-06-21 17:11:33 -0400, Andrew Dunstan wrote:
>>> I and a couple of colleagues have looked it over. As far as it goes the
>>> json fix looks kosher to me. I'll play with it some more.
>>
>> Cool.
>>
>> Any chance you could look at fixing the "structure" of the generated
>> expression "program". The recursive ExecEvalExpr() calls are really not ok...

By how much does the size of ExprEvalStep go down once you don't
inline the JSON structures as of 0004 in [1]?  And what of 0003?  The
JSON portions seem like the largest portion of the cake, though both
are must-fixes.

> Yes, but I don't guarantee to have a fix in time for Beta2.

IMHO, it would be nice to get something done for beta2.  Now the
thread is rather fresh and I guess that more performance study is 
required even for 0004, so..  Waiting for beta3 would a better move at
this stage.  Is somebody confident enough in the patches proposed?
0004 looks rather sane, seen from here, at least.

[1]: https://www.postgresql.org/message-id/20220617200605.3moq7dtxua5cxemv@alap3.anarazel.de
--
Michael