This is a discussion on [Again] Postgres performance problem within the Pgsql Performance forums, part of the PostgreSQL category; --> > > Isn't that the point of the documentation? I mean, if the existing, > > official manual has ...
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| > > Isn't that the point of the documentation? I mean, if the existing, > > official manual has been demonstrated (through countless mailing list > > help requests) to not sufficiently explain a given topic, shouldn't > > it be revised? Or it proves that no one bothers to read the docs. > > One thing that might help is a hyperlinked glossary > > so that people reading through the documentation can go straight to > > the postgres definition of dead tuple, index bloat, etc. > Yes and no. The official docs are more of a technical specification. > Short, simple and to the point so that if you know mostly what you're > doing you don't have to wade through a long tutorial to find the > answer. I find MySQL's documentation frustrating as hell because I > can never find just the one thing I wanna look for. Yes! MySQL documentation is maddening. This is why, I suspect, for products like Informix and DB2 IBM publishes two manuals (or roughly equivalent to two manuals): a "guide" and a "reference". > written as a tutorial. I.e. I have to pay the "stupid tax" when I > read their docs. Yep. > What I want to do is two fold. 1: fix the technical docs so they have > better explanations of each of the topics, without turning them into > huge tutorials. 2: Write a vacuuming tutorial that will be useful > should someone be new to postgresql and need to set up their system. > I think the tutorial should be broken into at least two sections, a > quick start guide and an ongoing maintenance and tuning section. ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@postgresql.org so that your message can get through to the mailing list cleanly |
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| -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Gavin M. Roy escribió: > How many backends do you have at any given time? Have you tried using > something like pgBouncer to lower backend usage? How about your IO > situation? Have you run something like sysstat to see what iowait is > at? backends arround 50 -100 I don't use pgBouncer yet. Sysstat reports veeery low io. Right now Im checking out fsm parameter, as Scott recomended. Seems there is the problem. > > On 9/11/07, Ruben Rubio <ruben@rentalia.com> wrote: > > Hi, > > I having the same problem I told here a few weeks before. Database is > using too much resources again. > > I do a vacumm full each day, but seems it is not working. I am preparing > an update to postgres 8.2.4 (actually I am using at 8.1.3, and tests for > update will need several days) > > Last time I had this problem i solved it stopping website, restarting > database, vacuumm it, run again website. But I guess this is going to > happen again. > > I would like to detect and solve the problem. Any ideas to detect it? > > Thanks in advance, > > > >> >> - ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@postgresql.org so that your message can get through to the mailing list cleanly >> >> >> -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFG7mx7Io1XmbAXRboRAn0VAJ4sGc1KCNlsbrybVbY/WfB+3XWBbwCfb7Z/ WNGyJCRo6zd26uR6FB6SA8o= =SYzs -----END PGP SIGNATURE----- ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match |
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| On Wed, Sep 12, 2007 at 03:01:12PM -0500, Erik Jones wrote: > > On Sep 12, 2007, at 2:19 PM, Frank Schoep wrote: > > >On Sep 12, 2007, at 9:07 PM, Scott Marlowe wrote: > >>On 9/12/07, Mikko Partio <mpartio@gmail.com> wrote: > >>>? > >>>Aren't you mixing up REINDEX and CLUSTER? > >> > >>? > >>Either one does what a vacuum full did / does, but generally does > >>it better. > > > >On topic of REINDEX / VACUUM FULL versus a CLUSTER / VACUUM ANALYZE > >I'd like to ask if CLUSTER is safe to run on a table that is in > >active use. > > > >After updating my maintenance scripts from a VACUUM FULL (add me to > >the list) to CLUSTER (which improves performance a lot) I noticed I > >was getting "could not open relation ?" errors in the log while the > >scripts ran so I reverted the change. This was on 8.1.9. > > You'd probably see the same behavior on 8.2.x. CLUSTER is not > transactionally safe so you don't want to run CLUSTER on tables that > are actively being used. I believe that's been fixed for 8.3. Actually, that's a bit over-conservative... what happens prior to 8.3 is that CLUSTER rewrites the table using it's XID for everything. That can break semantics for any transactions that are running in serializable mode; if you're just using the default isolation level of read committed, you're fine with CLUSTER. -- Decibel!, aka Jim C. Nasby, Database Architect decibel@decibel.org Give your computer some brain candy! www.distributed.net Team #1828 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.3 (FreeBSD) iD8DBQFG7nHudO30qud8SkgRAiswAKCgoMiT80Ei+6R/ZmAGYsQU/OBqGACg2GV5 3712UJ7hpSYBwMHeKFQh1yw= =Gpfr -----END PGP SIGNATURE----- |
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| On Thu, Sep 13, 2007 at 01:58:10AM -0400, Greg Smith wrote: > On Wed, 12 Sep 2007, Scott Marlowe wrote: > > >I'm getting more and more motivated to rewrite the vacuum docs. I think > >a rewrite from the ground up might be best... I keep seeing people > >doing vacuum full on this list and I'm thinking it's as much because of > >the way the docs represent vacuum full as anything. > > I agree you shouldn't start thinking in terms of how to fix the existing > documentation. I'd suggest instead writing a tutorial leading someone > through what they need to know about their tables first and then going > into how vacuum works based on that data. Take a look at the stuff at http://decibel.org/~decibel/pervasive/, it'd hopefully provide a useful starting point. -- Decibel!, aka Jim C. Nasby, Database Architect decibel@decibel.org Give your computer some brain candy! www.distributed.net Team #1828 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.3 (FreeBSD) iD8DBQFG7nK3dO30qud8SkgRAp4fAKCnj8v8Lq+uNr/vMr/fHCNaDlv27ACfWwXA MSu4PBo9tIjh8S+8ltZUFFg= =j6wC -----END PGP SIGNATURE----- |
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| On Mon, 2007-09-17 at 07:27 -0500, Decibel! wrote: > Take a look at the stuff at http://decibel.org/~decibel/pervasive/, it'd > hopefully provide a useful starting point. A bit offtrack, but I was reading the articles and noticed this in the bottom. Is this a typo or ... Making PostreSQL pervasive© 2005 Pervasive Software Inc ^^^^^^^^^ ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend |