Horton

Re: Import Statistics in postgres_fdw before resorting to sampling.

Etsuro Fujita <etsuro.fujita@gmail.com>

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From: Etsuro Fujita <etsuro.fujita@gmail.com>
To: Corey Huinker <corey.huinker@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, pgsql-hackers@postgresql.org, jkatz@postgresql.org, nathandbossart@gmail.com
Date: 2025-12-15T10:01:44Z
Lists: pgsql-hackers 
On Mon, Dec 15, 2025 at 5:01 AM Corey Huinker <corey.huinker@gmail.com> wrote:

>> Ah, I mean the case where the foreign table is an inheritance parent
>> on the *local* side.  In that case, the return would cause us to skip
>> the recursive ANALYZE (i.e., do_analyze_rel() with inh=true), leading
>> to no inherited stats.  I agree that the case is minor, but I don't
>> think that that's acceptable.

> When such a corner case occurs (stats import configured to true, but table is an inheritance parent), should we raise an error, or raise a warning and return false on the CanImportStats() call? I guess the answer may depend on the feedback we get.

As mentioned upthread, the FDW API that I proposed addresses this
issue; even in such a case it allows the FDW to import stats, instead
of doing the normal non-recursive ANALYZE, and then do the recursive
ANALYZE, for the inherited stats.

Best regards,
Etsuro Fujita