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

From Bruce Momjian
Subject Re: Performance (was: The New Slashdot Setup (includes MySql server))
Date
Msg-id 200005191506.LAA04864@candle.pha.pa.us
Whole thread Raw
In response to Re: Performance (was: The New Slashdot Setup (includes MySql server))  ("Matthias Urlichs" <smurf@noris.net>)
List pgsql-hackers
I would like to see if VACUUM ANALYZE helps.

> 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
> 


--  Bruce Momjian                        |  http://www.op.net/~candle pgman@candle.pha.pa.us               |  (610)
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