Re: Performance (was: The New Slashdot Setup (includes MySql server)) - Mailing list pgsql-hackers

From Matthias Urlichs
Subject Re: Performance (was: The New Slashdot Setup (includes MySql server))
Date
Msg-id 20000519134008.O27730@noris.de
Whole thread Raw
In response to RE: Performance (was: The New Slashdot Setup (includes MySql server))  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
Responses Re: Performance (was: The New Slashdot Setup (includes MySql server))  (The Hermit Hacker <scrappy@hub.org>)
Re: Performance (was: The New Slashdot Setup (includes MySql server))  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Hi,

Hiroshi Inoue:
> What does 'vacuum pg_index' show ?
> 
test=> vacuum pg_index;
NOTICE:  Skipping "pg_index" --- only table owner can VACUUM it
VACUUM

OK, so I suppose I should do it as the postgres user...
test=> vacuum pg_index;
VACUUM

The debug output says:
DEBUG:  --Relation pg_index--
DEBUG:  Pages 448: Changed 0, reaped 448, Empty 0, New 0; Tup 34: Vac 21443, Keep/VTL 0/0, Crash 0, UnUsed 0, MinLen
164,MaxLen 164;
 
Re-using: Free/Avail. Space 3574948/3567176; EndEmpty/Avail. Pages 0/447. CPU 0.46s/0.00u sec.
DEBUG:  Index pg_index_indexrelid_index: Pages 86; Tuples 34: Deleted 21443. CPU 0.05s/0.36u sec.
DEBUG:  Rel pg_index: Pages: 448 --> 1; Tuple(s) moved: 2. CPU 0.03s/0.03u sec.
DEBUG:  Index pg_index_indexrelid_index: Pages 86; Tuples 34: Deleted 2. CPU 0.01s/0.00u sec.

... which helped. A lot.

Thanks, everybody. The first quick benchmark run I did afterwards states
that PostgreSQL is now only half as fast as MySQL, instead of the factor
of 30 seen previously, on the MySQL benchmark test.  ;-)

-- 
Matthias Urlichs  |  noris network GmbH   |   smurf@noris.de  |  ICQ: 20193661
The quote was selected randomly. Really.       |        http://smurf.noris.de/
-- 
Dorian Graying:The unwillingness to gracefully allow one's body to show signs
of aging.        -Douglas Coupland, Generation X


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