pg_class.reltuples not reset by VACUUM?
| От | Jeff Boes |
|---|---|
| Тема | pg_class.reltuples not reset by VACUUM? |
| Дата | |
| Msg-id | b6v1p3$cp4$1@news.hub.org обсуждение исходный текст |
| Ответы |
Re: pg_class.reltuples not reset by VACUUM?
|
| Список | pgsql-admin |
I thought that VACUUM ANALYZE would always restore some sense of reality
to the internal statistics for a table. However ...
# select count(*) from job_queue;
count
-------
834
(1 row)
# select reltuples from pg_class where relname = 'job_queue';
reltuples
-----------
206277
(1 row)
# vacuum analyze job_queue;
# select reltuples from pg_class where relname = 'job_queue';
reltuples
-----------
2062xx (slightly larger number)
(1 row)
This is of concern to me mostly because:
# explain select * from job_queue;
NOTICE: QUERY PLAN:
Seq Scan on job_queue (cost=0.00..5989.77 rows=206277 width=95)
Obviously, the optimizer thinks that the table has 200k rows in it!
--
Jeff Boes vox 616.226.9550 ext 24
Database Engineer fax 616.349.9076
Nexcerpt, Inc. http://www.nexcerpt.com
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