Re: hot updates and fillfactor

Hi Fabrice,

> I do not understand why hot_updates value is not 0 for pg_database? Given that reloptions is empty for this table that means it has a default value of 100%

Maybe I didn't entirely understand your question, but why would you
assume they are somehow related?

According to the documentation [1][2]:

pg_class.reloptions:
  Access-method-specific options, as “keyword=value” strings

pg_stat_all_tables.n_tup_hot_upd:
  Number of rows HOT updated. These are updates where no successor
versions are required in indexes.

The value of n_tup_hot_upd is not zero because there are tuples that
were HOT-updated. That's it. You can read more about HOT here [3].

[1]: https://www.postgresql.org/docs/current/catalog-pg-class.html
[2]: https://www.postgresql.org/docs/current/monitoring-stats.html
[3]: https://www.postgresql.org/docs/current/storage-hot.html

--
Best regards,
Aleksander Alekseev