From: | Wael Khobalatte <wael(at)vendr(dot)com> |
---|---|
To: | Les <nagylzs(at)gmail(dot)com> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-performance(at)lists(dot)postgresql(dot)org |
Subject: | Re: Slow query, possibly not using index |
Date: | 2023-08-27 18:54:02 |
Message-ID: | CAJZ8yobjDP8zGa4V19ydHHTbE75tV_bE2vpkLj-=j-boZ6eQZg@mail.gmail.com |
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Lists: | pgsql-performance |
> Nobody ever deleted anything from this table. Since it was created, this
has been a write-only table.
does write-only include updates? that would create the dead rows tom is
referring to.
> I believe it is not actually using the index, because reading a single
(random?) entry from an index should not run for >10 minutes.
it is using the index. You can disable it, and see how long your query
takes ("set enable_indexonlyscan = off", optionally enable_indexscan too),
chances are it will take even longer. If somehow it does not, by luck, then
you no vacuum has run for a while, for some reason (perhaps canceled due to
frequent table activity?). That too you can check.
>
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