Re: slow queries on system tables

Поиск
Список
Период
Сортировка
От Adrian Klaver
Тема Re: slow queries on system tables
Дата
Msg-id 0eca5ab6-82cf-9768-6f09-0cb9998a1fdf@aklaver.com
обсуждение исходный текст
Ответ на Re: slow queries on system tables  (PegoraroF10 <marcos@f10.com.br>)
Ответы Re: slow queries on system tables  (PegoraroF10 <marcos@f10.com.br>)
Re: slow queries on system tables  (PegoraroF10 <marcos@f10.com.br>)
Список pgsql-general
On 8/23/19 2:47 PM, PegoraroF10 wrote:
> Coming back to my problem, today happened again, that search comes slow. 
> Explaining again, auto vacuum and auto analyse for pg_* tables are not 
> configured one by one, so its using that defaults of scale_factor = 0.2 
> and threshold = 50. Today, when that problem of speed came back, the 
> view pg_stat_sys_tables for pg_class table shows that it ran 415 times 
> autovacuum only this week and there are 75187 updates on this table. How 
> can I have been updated 75000 times this table only in a week ? What 

If you are still doing this:

https://www.postgresql.org/message-id/1563909633976-0.post%40n3.nabble.com

then it is not surprising.

> kind of statement does an update on this table ? And why did it run 415 
> times autovacuum and only 1 autoanalyse ?

Can you show the actual settings in postgresql.conf for:

autovacuum_analyze_threshold

autovacuum_analyze_scale_factor

Also do you have an include in postgresql.conf pointing to another file?

I know you said they are using the defaults but the scale_factor you 
show above is the default for autovacuum_vacuum_scale_factor. For 
autovacuum_analyze_scale_factor the default is 0.1, which makes wonder.

> relname    seq_scan    seq_tup_read    idx_scan    idx_tup_fetch    n_tup_ins 
> n_tup_upd    n_tup_del    n_tup_hot_upd    n_live_tup    n_dead_tup 
> n_mod_since_analyze    last_vacuum    last_autovacuum    last_analyze 
> last_autoanalyze    vacuum_count    autovacuum_count    analyze_count 
> autoanalyze_count
> pg_class    5395512    38598962913    616674711    2219978581    2243    75187    625    44008 
> 169891    5645    7435    NULL    2019-08-22 19:58:48.497317    NULL    2019-08-22 
> 13:03:02.770579    0    415    0    1
> 
> 
> ------------------------------------------------------------------------
> Sent from the PostgreSQL - general mailing list archive 
> <https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html> at 
> Nabble.com.


-- 
Adrian Klaver
adrian.klaver@aklaver.com



В списке pgsql-general по дате отправления:

Предыдущее
От: Michael Lewis
Дата:
Сообщение: Re: slow queries on system tables
Следующее
От: PegoraroF10
Дата:
Сообщение: Re: slow queries on system tables