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From: Richard Guo <guofenglinux@gmail.com>
Date: Thu, 27 Mar 2025 16:48:03 +0900
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Subject: Re: Remove vardata parameters from eqjoinsel_inner
To: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
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On Fri, Feb 21, 2025 at 7:04=E2=80=AFPM Ilia Evdokimov
<ilya.evdokimov@tantorlabs.com> wrote:
> When calculating selectivity for an inner equijoin, we call
> eqjoinsel_inner, which uses unused parameters vardata1 and vardata2.
> These parameters might have been left behind accidentally when we moved
> getting sslots out of the function. I suggest removing them, as they can
> be added back at any time if needed. I attached patch with fixes.

Yeah, these parameters haven't been used since a314c3407, when we
moved get_variable_numdistinct and get_attstatsslot out of
eqjoinsel_inner and eqjoinsel_semi to avoid repetitive information
lookup when we call both eqjoinsel_inner and eqjoinsel_semi.

I'm wondering whether we should also remove parameter vardata1 from
eqjoinsel_semi.  vardata2 is still needed though to clamp nd2 to be
not more than the rel's row estimate.

Thanks
Richard