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

On 2022-07-05 Tu 14:36, Andres Freund wrote:
> Hi,
>
> On 2022-06-24 10:29:06 -0400, Andrew Dunstan wrote:
>> On 2022-06-23 Th 21:51, Andres Freund wrote:
>>> On 2022-06-23 16:38:12 +0900, Michael Paquier wrote:
>>>> On Tue, Jun 21, 2022 at 05:41:07PM -0400, Andrew Dunstan wrote:
>>>>> 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..
>>> I don't think there's a whole lot of performance study needed for 0004 - the
>>> current state is obviously wrong.
>>>
>>> I think Andrew's beta 2 comment was more about my other architectural
>>> complains around the json expression eval stuff.
>>
>> Right. That's being worked on but it's not going to be a mechanical fix.
> Any updates here?

Not yet. A colleague and I are working on it. I'll post a status this
week if we can't post a fix.

>
> I'd mentioned the significant space use due to all JsonCoercionsState for all
> the types. Another related aspect is that this code is just weird - the same
> struct name (JsonCoercionsState), nested in each other?
>
> struct JsonCoercionsState
> {
> struct JsonCoercionState
> {
> JsonCoercion *coercion; /* coercion expression */
> ExprState *estate; /* coercion expression state */
> } null,
> string,
> numeric ,
> boolean,
> date,
> time,
> timetz,
> timestamp,
> timestamptz,
> composite;
> } coercions; /* states for coercion from SQL/JSON item
> * types directly to the output type */
>
> Also note the weird numeric indentation that pgindent does...

Yeah, we'll try to fix that.

>
>
>> The attached very small patch applies on top of your 0002 and deals with
>> the FmgrInfo complaint.
> Now that the FmgrInfo is part of a separately allocated struct, that doesn't
> seem necessary anymore.

Right, but you complained that we should do it the same way as it's done
elsewhere, so I thought I'd do that anyway.

cheers

andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com