Re: Where does data in pg_stat_user_tables come from?
| От | Josh Berkus | 
|---|---|
| Тема | Re: Where does data in pg_stat_user_tables come from? | 
| Дата | |
| Msg-id | 4C92645A.1040208@agliodbs.com обсуждение исходный текст | 
| Ответ на | Re: Where does data in pg_stat_user_tables come from? (Alvaro Herrera <alvherre@commandprompt.com>) | 
| Ответы | Re: Where does data in pg_stat_user_tables come from? Re: Where does data in pg_stat_user_tables come from? | 
| Список | pgsql-performance | 
> It's been pure nonsense in this thread.  Please show an example of
> what's not working.
1) Init a postgresql 8.3 with autovacuum disabled.
2) Load a backup of a database into that PostgreSQL.
3) Check pg_stat_user_tables.  n_live_tup for all tables will be 0.
4) VACUUM ANALYZE the whole database.
5) n_live_tup will *still* be 0.  Whereas reltuples in pg_class will be
reasonable accurate.
> Um ... it updates the last_autovacuum and last_autoanalyze columns,
> but the others are not its responsibility.
Right. I'm contending that ANALYZE *should* update those columns.
Current behavior is unintuitive and makes the stats in
pg_stat_user_tables almost useless, since you can never get even
approximately a coherent snapshot of data for all tables.
--
                                  -- Josh Berkus
                                     PostgreSQL Experts Inc.
                                     http://www.pgexperts.com
		
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