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.

Ah, you're right. This table does contain the statistics for it. Everything is okay then. Sorry for the confusion.

Regards,
Ilia Evdokimov,
Tantor Labs LLC.