Re: Increase value of OUTER_VAR

On 3/4/21 4:16 PM, Tom Lane wrote:
> Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com> writes:
>> IMO just bumping up the constants from ~65k to 1M is a net loss, for
>> most users. We add this to bitmapsets, which means we're using ~8kB with
>> the current values, but this jumps to 128kB with this higher value. This
>> also means bms_next_member etc. have to walk much more memory, which is
>> bound to have some performance impact for everyone.
>
> Hmm, do we really have any places that include OUTER_VAR etc in
> bitmapsets? They shouldn't appear in relid sets, for sure.
> I agree though that if they did, this would have bad performance
> consequences.
>

Hmmm, I don't know. I mostly assumed that if I do pull_varnos() it would
include those values. But maybe that's not supposed to happen.

> I still think the negative-special-values approach is better.
> If there are any places that that would break, we'd find out about
> it in short order, rather than having a silent performance lossage.
>

OK

regards

--
Tomas Vondra
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