Re: large number dead tup - Postgres 9.5

Hi guys,

select schemaname,relname,n_live_tup, n_dead_tup from pg_stat_all_tables where relname = 'parts';

schemaname relname       n_live_tup n_dead_tup 
---------- ------------- ---------- ---------- 
public     parts 191623953  182477402 

See the large number of dead_tup?

My autovacuum parameters are:

"autovacuum_vacuum_threshold" : "300",
"autovacuum_analyze_threshold" : "200",
"autovacuum_vacuum_scale_factor" : "0.005",
"autovacuum_analyze_scale_factor" : "0.002", 

Table size: 68 GB

Why does that happen? Autovacuum shouldn't take care of dead_tuples?

Because of that the table is very slow... 

When I do a select on that table it doesn't use an index, for example:

\d parts;

    "index_parts_id" btree (company_id)
    "index_parts_id_and_country" btree (company_id, country) 

 

explain select * from parts WHERE company_id = 12;

Seq Scan on parts  (cost=0.00..6685241.40 rows=190478997 width=223)
  Filter: (company_id = 12)