| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | David Rowley <dgrowleyml(at)gmail(dot)com> |
| Cc: | Jean Landercy - BEEODIVERSITY <jean(dot)landercy(at)beeodiversity(dot)com>, "pgsql-hackers(at)lists(dot)postgresql(dot)org" <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Sudden database error with COUNT(*) making Query Planner crashes: variable not found in subplan target list |
| Date: | 2022-06-07 21:24:06 |
| Message-ID: | 1339803.1654637046@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
I wrote:
> That ... is pretty quirky already. How did it prefer a scan with cost
> 19.32 over one with cost 9.39? Seems like we've got a bug here somewhere.
> The change in estimated rowcount is rather broken, too.
Ah, false alarm. I can reproduce your results if I stick an ANALYZE
between the first and second EXPLAIN. So probably your change in
estimated rowcount and hence cost can be explained by an auto-analyze
coming along at just the right time.
Also, if I fill the geom and location columns with non-null data,
the planner stops preferring those indexes.
So now I'm guessing that the OP's data *was* mostly null, and the
planner preferred the gist indexes because they were smallest,
and then tripped over the nonreturnable-column bug.
regards, tom lane
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