Re: Understanding pg_stat_io.evictions

At Fri, 28 Jul 2023 10:36:46 +0000, "Daniel Westermann (DWE)" <daniel(dot)westermann(at)dbi-services(dot)com> wrote in
> postgres=# insert into t select i, md5(i::text), md5(i::text), md5(i::text) from generate_series(1,1000000) i;
..
> client backend | 207 | normal
> client backend | 0 | vacuum
>
> Shouldn't these evictions show up under context blkwrite? The description in docs is:

No, that's not the case because INSERT doesn't execute a bulk
write. It is is only performed during COPY FROM, and the write side of
some other comands, such as CREATE AS (and some internal table-copy
operations.).

> As far as I understand this, a ring buffer is used in this case. Do I miss something?

Maybe you're confusiong it with bulk-read cases?

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center