Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-05-04 Thread Greg Smith
On Fri, 4 May 2007, Michael Stone wrote: P4 2.4GHz 107ms Xeon 3GHz 100ms Opteron 275 65ms Athlon X2 4600 61ms PIII 1GHz 265ms Opteron 250 39ms something seems inconsistent here. I don't see what you mean. The PIII results are exactly what I'd expect, and I wouldn'

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-05-04 Thread Sebastian Hennebrueder
Josh Berkus schrieb: > Sebastian, > > >> Before inventing a hyper tool, we might consider to provide 3-5 example >> szenarios for common hardware configurations. This consumes less time >> and be discussed and defined in a couple of days. This is of course not >> the correct option for a brandn

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-05-04 Thread Josh Berkus
Sebastian, > Before inventing a hyper tool, we might consider to provide 3-5 example > szenarios for common hardware configurations. This consumes less time > and be discussed and defined in a couple of days. This is of course not > the correct option for a brandnew 20 spindle Sata 10.000 Raid 10

Re: [PERFORM] Query performance problems with partitioned tables

2007-05-04 Thread Merlin Moncure
On 5/4/07, Scott Marlowe <[EMAIL PROTECTED]> wrote: On Thu, 2007-05-03 at 21:37, Merlin Moncure wrote: > On 5/3/07, Fei Liu <[EMAIL PROTECTED]> wrote: > > Hello, Andreas, I too am having exactly the same issue as you do. > > Comparing my partitioned and plain table performance, I've found that >

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-05-04 Thread Sebastian Hennebrueder
[EMAIL PROTECTED] schrieb: > On Tue, 1 May 2007, Carlos Moreno wrote: > >>> large problem from a slog perspective; there is no standard way even >>> within Linux to describe CPUs, for example. Collecting available disk >>> space information is even worse. So I'd like some help on this >>> port

Re: [PERFORM] Index not being used in sorting of simple table

2007-05-04 Thread Paul Smith
At 16:26 04/05/2007, you wrote: Paul Smith wrote: Why doesn't it use the other index? If use 'set enable_seqscan=0' then it does. Just a guess, but is the table clustered on column a? Maybe not explicitly, but was it loaded from data that was sorted by a? I wouldn't have thought so - a is p

Re: [PERFORM] Index not being used in sorting of simple table

2007-05-04 Thread Tom Lane
Paul Smith <[EMAIL PROTECTED]> writes: > If I do > EXPLAIN SELECT * FROM x ORDER BY a; > it says > Index Scan using y on x (cost=0.00..2903824.15 rows=1508057 width=152) > That's what I'd expect > However, if I do > EXPLAIN SELECT * FROM x ORDER BY b; > it says > Sort (cost=711557.34..715327.

Re: [PERFORM] Index not being used in sorting of simple table

2007-05-04 Thread Heikki Linnakangas
Paul Smith wrote: Why doesn't it use the other index? If use 'set enable_seqscan=0' then it does. Just a guess, but is the table clustered on column a? Maybe not explicitly, but was it loaded from data that was sorted by a? Analyzer calculates the correlation between physical order and each

Re: [PERFORM] Query performance problems with partitioned tables

2007-05-04 Thread Scott Marlowe
On Thu, 2007-05-03 at 21:37, Merlin Moncure wrote: > On 5/3/07, Fei Liu <[EMAIL PROTECTED]> wrote: > > Hello, Andreas, I too am having exactly the same issue as you do. > > Comparing my partitioned and plain table performance, I've found that > > the plain tables perform about 25% faster than parti

[PERFORM] Index not being used in sorting of simple table

2007-05-04 Thread Paul Smith
This is in Postgres 8.1.5 I have a table like CREATE TABLE x (a VARCHAR, b VARCHAR, c VARCHAR); CREATE INDEX y on x(a); CREATE INDEX z on x(b); There are over a million rows in 'x'. Neither a nor b are unique. There are probably about 20 or so distinct values of a and 30 or so distinct values

Re: [PERFORM] pg_stat_* collection

2007-05-04 Thread Michael Stone
On Fri, May 04, 2007 at 12:53:55AM -0400, Greg Smith wrote: It's also completely inappropriate for any environment I work in, because there really is no thought of security whatsoever in the whole thing. That makes it sound more like snmp, not less. :-) Mike Stone ---

Re: [PERFORM] Feature Request --- was: PostgreSQL Performance Tuning

2007-05-04 Thread Michael Stone
On Fri, May 04, 2007 at 12:33:29AM -0400, Greg Smith wrote: -bash-3.00$ psql postgres=# \timing Timing is on. postgres=# select count(*) from generate_series(1,10,1); count 10 (1 row) Time: 106.535 ms There you go, a completely cross-platform answer. You should run the stat