Re: Vacuum statistics

Hi! Thank you for review!

On 07.11.2024 17:49, Ilia Evdokimov wrote:
>
> Thank you for fixing it.
>
> 1) I have found some typos in the test output files (out-files) when
> running 'make check' and 'make check-world'. These typos might cause
> minor discrepancies in test results. You may already be aware of them,
> but I wanted to bring them to your attention in case they haven't been
> noticed. I believe these can be fixed quickly.
>
Yes, I'll fix it)
>
> 2) Additionally, I observed that when we create a table and insert
> some rows, executing the VACUUM FULL command does not update the
> information in the 'pg_stat_get_vacuum_tables' However, running the
> VACUUM command does update this information as expected. This seems
> inconsistent, and it might be a bug.
>
> Example:
> CREATE TABLE t (i INT, j INT) WITH (autovacuum_enabled = false);
> INSERT INTO t SELECT i/10, i/100 FROM GENERATE_SERIES(1,1000000) i;
> SELECT * FROM pg_stat_get_vacuum_tables WHERE relname = 't';
> schema | relname |    relid | total_blks_read | .........
> -----------+------------+---------+----------------------+---------
>    public | t            | 21416 |                       0 | ......
> (1 row)
>
> VACUUM FULL;
> SELECT * FROM pg_stat_get_vacuum_tables WHERE relname = 't';
> schema | relname |    relid | total_blks_read | .........
> -----------+------------+---------+----------------------+---------
>    public | t            | 21416 |                       0 | ......
> (1 row)
>
> VACUUM;
> SELECT * FROM pg_stat_get_vacuum_tables WHERE relname = 't';
> schema | relname |    relid | total_blks_read | .........
> -----------+------------+---------+----------------------+---------
>    public | t            | 21416 |                 4425 | ......
> (1 row)
>
>
vacuum full operation doesn't call a vacuum operation, so we can't
collect statistics for it. Furthermore, this is a different operation
than vacuum because it completely rebuilds the table and indexes, so it
looks like your previous table and its indexes were completely removed.
To sum up, I think it isn't a bug that the statistics aren't showing here.

--
Regards,
Alena Rybakina
Postgres Professional