Re: [PERFORM] slow update

2005-10-13 Thread Patrick Hatcher
Thanks. No foreign keys and I've been bitten by the mismatch datatypes and checked that before sending out the message :) Patrick Hatcher Development Manager Analytics/MIO Macys.com Tom Lane

Re: [PERFORM] slow update

2005-10-13 Thread Tom Lane
Patrick Hatcher <[EMAIL PROTECTED]> writes: > Pg 7.4.5 > Trying to do a update of fields on 23M row database. > Is it normal for this process to take 16hrs and still clocking? Are there foreign keys pointing at the table being updated? If so, failure to index the referencing columns could create

[PERFORM] slow update

2005-10-13 Thread Patrick Hatcher
Pg 7.4.5 RH 7.3 Quad Xeon 3Gz 12G ram Trying to do a update of fields on 23M row database. Is it normal for this process to take 16hrs and still clocking? Both join fields are indexed and I have removed any indexes on the updated columns. Also both tables are vacuumed regularly. I'm weary to can

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Andrew Sullivan
On Thu, Oct 13, 2005 at 03:14:44PM +0200, Csaba Nagy wrote: > In any case, I suppose that those disk pages should be in OS cache > pretty soon and stay there, so I still don't understand why the disk > usage is 100% in this case (with very low CPU activity, the CPUs are > mostly waiting/idle)... th

Re: [PERFORM] Server misconfiguration???

2005-10-13 Thread Andrew Sullivan
On Mon, Oct 10, 2005 at 05:31:10PM +0300, Andy wrote: > I read some tuning things, I made the things that are written there, but I > think that there improvements can be made. Have you tried the suggestions people made? Because if I were you, I'd be listing very carefully to what Chris and Tom w

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Matthew Nuzum
On 10/13/05, Csaba Nagy <[EMAIL PROTECTED]> wrote: > On Thu, 2005-10-13 at 14:40, Andrew Sullivan wrote: > > On Thu, Oct 13, 2005 at 10:15:03AM +0200, Csaba Nagy wrote: > > > And how would the analyze help in finding this out ? I thought it would > > > only show me additionally the actual timings,

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Csaba Nagy
Thanks Andrew, this explanation about the dead rows was enlightening. Might be the reason for the slowdown I see on occasions, but not for the case which I was first observing. In that case the updated rows are different for each update. It is possible that each row has a few dead versions, but not

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Andrew Sullivan
On Thu, Oct 13, 2005 at 10:15:03AM +0200, Csaba Nagy wrote: > > OK, this sounds interesting, but I don't understand: why would an update > "chase down a lot of dead tuples" ? Should I read up on some docs, cause > I obviously don't know enough about how updates work on postgres... Right. Here's

Re: [PERFORM] Optimizer misconfigured ?

2005-10-13 Thread Richard Huxton
Nörder-Tuitje wrote: Hello, I have a strange effect on upcoming structure : People will be wanting the output of EXPLAIN ANALYSE on that query. They'll also ask whether you've VACUUMed, ANALYSEd and configured your postgresql.conf correctly. -- Richard Huxton Archonet Ltd ---

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Markus Wollny
[EMAIL PROTECTED] wrote: > Next we'll upgrade the postgres hardware, and then I'll come > back to report if it's working better... sorry for the noise for now. There have been some discussions about which hardware suits PostgreSQL's needs best under certain load-characteristics. We have experienc

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Markus Wollny
[EMAIL PROTECTED] wrote: >>> Have you tried reindexing your active tables? > It will cause some performance hit while you are doing it. It > sounds like something is bloating rapidly on your system and > the indexes is one possible place that could be happening. You might consider using contrib/

[PERFORM] Optimizer misconfigured ?

2005-10-13 Thread Nörder-Tuitje , Marcus
Title: Optimizer misconfigured ? Hello, I have a strange effect on upcoming structure : DEX_OBJ  ---< DEX_STRUCT >--- DEX_LIT DEX_OBJ : 100 records (#DOO_ID, DOO_NAME) DEX_STRUCT : 2,5 million records  (#(DST_SEQ, FK_DOO_ID, FK_LIT_ID)) DEX_LIT : 150K records  (#LIT_ID, LIT_TEXT)

Re: [PERFORM] Help tuning postgres

2005-10-13 Thread Csaba Nagy
[snip] > Yes, but it could be a disk issue because you're doing more work than > you need to. If your UPDATEs are chasing down a lot of dead tuples, > for instance, you'll peg your I/O even though you ought to have I/O > to burn. OK, this sounds interesting, but I don't understand: why would an u