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

2007-04-27 Thread david
On Fri, 27 Apr 2007, Josh Berkus wrote: Dan, Yes, this is the classic problem.  I'm not demanding anyone pick up the ball and jump on this today, tomorrow, etc.. I just think it would be good for those who *could* make a difference to keep those goals in mind when they continue.  If you have t

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

2007-04-27 Thread Josh Berkus
Dan, > Yes, this is the classic problem.  I'm not demanding anyone pick up the > ball and jump on this today, tomorrow, etc.. I just think it would be > good for those who *could* make a difference to keep those goals in mind > when they continue.  If you have the right mindset, this problem will

Re: [PERFORM] Very specific server situation

2007-04-27 Thread Tom Lane
"Mauro N. Infantino" <[EMAIL PROTECTED]> writes: > What we basically have is a site where each user has a box with links to > other randomly selected users. Whenever a box from a user is shown, a SPs is > executed: a credit is added to that user and a credit is substracted from > the accounts of th

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

2007-04-27 Thread Dan Harris
Bill Moran wrote: In response to Dan Harris <[EMAIL PROTECTED]>: Why does the user need to manually track max_fsm_pages and max_fsm_relations? I bet there are many users who have never taken the time to understand what this means and wondering why performance still stinks after vacuuming the

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

2007-04-27 Thread Josh Berkus
Bill, > The only one that seems practical (to me) is random_page_cost. The > others are all configuration options that I (as a DBA) want to be able > to decide for myself. Actually, random_page_cost *should* be a constant "4.0" or "3.5", which represents the approximate ratio of seek/scan spee

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

2007-04-27 Thread Ray Stell
On Fri, Apr 27, 2007 at 02:40:07PM -0400, Kevin Hunter wrote: > out that many run multiple postmasters or have other uses for the > machines in question), but perhaps it could send a message (email?) > along the lines of "Hey, I'm currently doing this many of X > transactions, against this mu

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

2007-04-27 Thread Kevin Hunter
At 10:36a -0400 on 27 Apr 2007, Tom Lane wrote: That's been proposed and rejected before, too; the main problem being that initdb is frequently a layer or two down from the user (eg, executed by initscripts that can't pass extra arguments through, even assuming they're being invoked by hand in th

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

2007-04-27 Thread Bill Moran
In response to Dan Harris <[EMAIL PROTECTED]>: > Michael Stone wrote: > > On Fri, Apr 27, 2007 at 09:27:49AM -0400, Carlos Moreno wrote: > >> Notice that the second part of my suggestion covers this --- have > >> additional > >> switches to initdb > > > If the person knows all that, why wouldn't

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

2007-04-27 Thread Josh Berkus
Dan, > Exactly..  What I think would be much more productive is to use the > great amount of information that PG tracks internally and auto-tune the > parameters based on it.  For instance: *Everyone* wants this. The problem is that it's very hard code to write given the number of variables. I

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

2007-04-27 Thread Dan Harris
Michael Stone wrote: On Fri, Apr 27, 2007 at 09:27:49AM -0400, Carlos Moreno wrote: Notice that the second part of my suggestion covers this --- have additional switches to initdb If the person knows all that, why wouldn't they know to just change the config parameters? Exactly.. What I

[PERFORM] Very specific server situation

2007-04-27 Thread Mauro N. Infantino
Hi, We're facing some perfomance problems with the database for a web site with very specific needs. First of all, we're using version 8.1 in a server with 1GB of RAM. I know memory normally should be more, but as our tables are not so big (as a matter of fact, they are small) I think the solution

Re: [PERFORM] How can fixed and variable width columns perform similarly?

2007-04-27 Thread Tom Lane
"Siddharth Anand" <[EMAIL PROTECTED]> writes: > My question wasn't phrased clearly. Oracle exhibits a performance > degradation for very large-sized fields (CLOB types that I equate to > PostGres' text type) when compared with the performance of field types > like varchar that handle a max characte

Re: [PERFORM] How can fixed and variable width columns perform similarly?

2007-04-27 Thread Siddharth Anand
Hi Tom, My question wasn't phrased clearly. Oracle exhibits a performance degradation for very large-sized fields (CLOB types that I equate to PostGres' text type) when compared with the performance of field types like varchar that handle a max character limit of a few thousand bytes in Oracle. It

Re: [PERFORM] How can fixed and variable width columns perform similarly?

2007-04-27 Thread Dave Dutcher
I think the manual is implying that if you store a value like "Sid" in a field either of type varchar(128) or type text there is no performance difference. The manual is not saying that you get the same performance storing a 500k text field as when you store the value "Sid". Dave -Original

Re: [PERFORM] [Fwd: ] How

2007-04-27 Thread Richard Huxton
Siddharth Anand wrote: Hi! I read the link below and am puzzled by or curious about something. http://www.postgresql.org/docs/8.1/interactive/datatype-character.html The Tip below is intriguing "Tip: There are no performance differences between these three types, apart from the increased stora

Re: [PERFORM] How can fixed and variable width columns perform similarly?

2007-04-27 Thread Tom Lane
"Siddharth Anand" <[EMAIL PROTECTED]> writes: > How can a field that doesn't have a limit like "text" perform similarly to > char varying(128), for example? At some point, we need to write data to > disk. The more data that needs to be written, the longer the disk write > will take, especially when

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

2007-04-27 Thread Jim Nasby
On Apr 27, 2007, at 3:30 PM, Michael Stone wrote: On Fri, Apr 27, 2007 at 09:27:49AM -0400, Carlos Moreno wrote: Notice that the second part of my suggestion covers this --- have additional switches to initdb so that the user can tell it about estimates on how the DB will be used: estimated

[PERFORM] How can fixed and variable width columns perform similarly?

2007-04-27 Thread Siddharth Anand
Hi! I read the link below and am puzzled by or curious about something. http://www.postgresql.org/docs/8.1/interactive/datatype-character.html The Tip below is intriguing "Tip: There are no performance differences between these three types, apart from the increased storage size when using the bl

[PERFORM] [Fwd: ] How

2007-04-27 Thread Siddharth Anand
Hi! I read the link below and am puzzled by or curious about something. http://www.postgresql.org/docs/8.1/interactive/datatype-character.html The Tip below is intriguing "Tip: There are no performance differences between these three types, apart from the increased storage size when using the bl

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

2007-04-27 Thread Michael Stone
On Fri, Apr 27, 2007 at 07:36:52AM -0700, Mark Lewis wrote: Maybe he's looking for a switch for initdb that would make it interactive and quiz you about your expected usage-- sort of a magic auto-configurator wizard doohicky? I could see that sort of thing being nice for the casual user or newbi

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

2007-04-27 Thread H.J. Sanders
Hello. Just my 2 cents, and not looking to the technical aspects: setting up PSQL is the weakest point of PSQL as we have experienced ourself, once it is running it is great. I can imagine that a lot of people of stops after their first trials after they have experienced the troubles and perfo

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

2007-04-27 Thread Mark Lewis
Maybe he's looking for a switch for initdb that would make it interactive and quiz you about your expected usage-- sort of a magic auto-configurator wizard doohicky? I could see that sort of thing being nice for the casual user or newbie who otherwise would have a horribly mis-tuned database. The

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

2007-04-27 Thread Tom Lane
Carlos Moreno <[EMAIL PROTECTED]> writes: > Tom Lane wrote: >> But >> the fundamental problem remains that we don't know that much about >> how the installation will be used. > Notice that the second part of my suggestion covers this --- have > additional switches to initdb That's been proposed

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

2007-04-27 Thread Michael Stone
On Fri, Apr 27, 2007 at 09:27:49AM -0400, Carlos Moreno wrote: Notice that the second part of my suggestion covers this --- have additional switches to initdb so that the user can tell it about estimates on how the DB will be used: estimated size of the DB, estimated percentage of activity tha

Re: [PERFORM] What`s wrong with JFS configuration?

2007-04-27 Thread Jim Nasby
Adding -performance back in so others can learn. On Apr 26, 2007, at 9:40 AM, Paweł Gruszczyński wrote: Jim Nasby napisał(a): On Apr 25, 2007, at 8:51 AM, Paweł Gruszczyński wrote: where u6 stores Fedora Core 6 operating system, and u0 stores 3 partitions with ext2, ext3 and jfs filesystem.

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

2007-04-27 Thread Carlos Moreno
Tom Lane wrote: Carlos Moreno <[EMAIL PROTECTED]> writes: ... But, wouldn't it make sense that the configure script determines the amount of physical memory and perhaps even do a HD speed estimate to set up defaults that are closer to a performance-optimized configuration? No. Most

Re: [PERFORM] Usage up to 50% CPU

2007-04-27 Thread Michael Stone
On Fri, Apr 27, 2007 at 07:23:41PM +0930, Shane Ambler wrote: I would think that as you are sitting and watching the cpu usage, your query would seem to taking a while to run, leading me to wonder if you are getting a full table scan that is causing pg to wait for disk response? If so, you pro

Re: [PERFORM] Usage up to 50% CPU

2007-04-27 Thread Shane Ambler
Magnus Hagander wrote: On Fri, Apr 27, 2007 at 08:10:48AM +, Andres Retzlaff wrote: Hi Magnus, in this case each CPU goes up to 50%, giveing me 50% total usage. I was specting as you say 1 query 100% cpu. Any ideas? No. 1 query will only use 100% of *one* CPU, which means 50% total usa

Re: [PERFORM] Usage up to 50% CPU

2007-04-27 Thread Magnus Hagander
On Fri, Apr 27, 2007 at 08:10:48AM +, Andres Retzlaff wrote: > Hi Magnus, > > in this case each CPU goes up to 50%, giveing me 50% total usage. I was > specting as you say 1 query 100% cpu. > > Any ideas? No. 1 query will only use 100% of *one* CPU, which means 50% total usage. You need at

Re: [PERFORM] Usage up to 50% CPU

2007-04-27 Thread Andres Retzlaff
Hi Magnus, in this case each CPU goes up to 50%, giveing me 50% total usage. I was specting as you say 1 query 100% cpu. Any ideas? Andrew On Fri, Apr 27, 2007 at 04:43:06AM +, Andres Retzlaff wrote: > Hi, > > I have pg 8.1.4 running in > Windows XP Pro > wirh a Pentium D > > and I notic

Re: [PERFORM] Usage up to 50% CPU

2007-04-27 Thread Magnus Hagander
On Fri, Apr 27, 2007 at 04:43:06AM +, Andres Retzlaff wrote: > Hi, > > I have pg 8.1.4 running in > Windows XP Pro > wirh a Pentium D > > and I notice that I can not use more than 50% of the cpus (Pentium D has 2 > cpus), how can I change the settings to use the 100% of it. A single query w

Re: Filesystem fragmentation (Re: [PERFORM] Fragmentation of WAL files)

2007-04-27 Thread Florian Weimer
* Bill Moran: > To clarify my viewpoint: > To my knowledge, there is no Unix filesystem that _suffers_ from > fragmentation. Specifically, all filessytems have some degree of > fragmentation that occurs, but every Unix filesystem that I am aware of > has built-in mechanisms to mitigate this and p