On 08/13/2018 11:07 AM, Raghavendra Rao J S V wrote:
Hi All,
We are using postgres *9.2* version on *Centos *operating system. We
have around *1300+* tables.We have following auto vacuum settings are
enables. Still few of the tables(84 tables) which are always busy are
not vacuumed.Dead tuples in those tables are more than 5000. Due to
that tables are bloating and observed few areas has performance
degradation.
You don't say how large the tables are, so it's impossible to say
whether 5000 dead tuples is excessive or not. IMHO it's a negligible
amount and should not lead to excessive bloat or issues.
A certain amount of wasted is expected - it's a trade-off between
immediate and delayed cleanup. If you delay the cleanup a bit, it's
going to be more efficient overall.
It's also unclear why the tables are not vacuumed - it may easily be due
to all the autovacuum workers being constantly busy, unable to cleanup
all tables in a timely manner. In that case lowering the threshold is
not going to help, on the contrary.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
