Re: hash aggregation - Mailing list pgsql-performance

From Korisk
Subject Re: hash aggregation
Date
Msg-id 846851350052668@web19g.yandex.ru
Whole thread Raw
In response to Re: hash aggregation  (Ondrej Ivanič <ondrej.ivanic@gmail.com>)
List pgsql-performance
> What I can not understand is why the seq scan's estimated cost is
> better the index scan's one. It depends on the number of pages in
> index/relation. May be the index is heavily bloated?
Mm i don't know how to see bloating level. But the index was created by
create index on hashcheck using btree (name)
after the table population.

Sizes:
hashes=# select pg_total_relation_size('hashcheck');
 pg_total_relation_size
------------------------
             2067701760
(1 row)

hashes=# select pg_total_relation_size('hashcheck_name_rev_idx');
 pg_total_relation_size
------------------------
              629170176
(1 row)



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