Re: Vacuum statistics

Hi!

On 16.10.2024 14:01, Alena Rybakina wrote:
>>
>> Thank you for rebasing.
>>
>> I have noticed that when I create a table or an index on this table,
>> there is no information about the table or index in
>> pg_stat_vacuum_tables and pg_stat_vacuum_indexes until we perform a
>> VACUUM.
>>
>> Example:
>>
>> CREATE TABLE t (i INT, j INT);
>> INSERT INTO t SELECT i/10, i/100 FROM GENERATE_SERIES(1,1000000) i;
>> SELECT * FROM pg_stat_vacuum_tables WHERE relname = 't';
>> ....
>> (0 rows)
>> CREATE INDEX ON t (i);
>> SELECT * FROM pg_stat_vacuum_indexes WHERE relname = 't_i_idx';
>> ...
>> (0 rows)
>>
>> I can see the entries after running VACUUM or executing
>> autovacuum. or when autovacuum is executed. I would suggest adding a
>> line about the relation even if it has not yet been processed by
>> vacuum. Interestingly, this issue does not occur with
>> pg_stat_vacuum_database:
>>
>> CREATE DATABASE example_db;
>> SELECT * FROM pg_stat_vacuum_database WHERE dbname = 'example_db';
>> dboid |       dbname | ...
>>  ...      | example_db | ...
>> (1 row)
>>
>> BTW, I recommend renaming the view pg_stat_vacuum_database to
>> pg_stat_vacuum_database_S_  for consistency with
>> pg_stat_vacuum_tables and pg_stat_vacuum_indexes
>>
> Thanks for the review. I'm investigating this. I agree with the
> renaming, I will do it in the next version of the patch.
>
I fixed it. I added the left outer join to the vacuum views and for
converting the coalesce function from NULL to null values.

I also fixed the code in getting database statistics - we can get it
through the existing pgstat_fetch_stat_dbentry function and fixed couple
of comments.

I attached a diff file, as well as new versions of patches.

--
Regards,
Alena Rybakina
Postgres Professional