[PERFORM] many instances or many databases or many users?

2007-02-13 Thread ismo . tuononen
Hi, I have used postgresql some years now, but only small databases and only one database per instance and one user per database. Now we have a server reserved only for postgresql, and I'm wondering if it is better to set up: - only one instance and many databases or - many instances and only

Re: [PERFORM] many instances or many databases or many users?

2007-02-13 Thread Heikki Linnakangas
[EMAIL PROTECTED] wrote: Now we have a server reserved only for postgresql, and I'm wondering if it is better to set up: - only one instance and many databases or - many instances and only one database/instance or - one instance, one database and many users It depends. One instance should

Re: [PERFORM] cube operations slower than geo_distance() on production server

2007-02-13 Thread Merlin Moncure
On 2/12/07, Mark Stosberg [EMAIL PROTECTED] wrote: Merlin Moncure wrote: Here the basic query I'm using: SELECT -- 1609.344 is a constant for meters per mile cube_distance( (SELECT earth_coords from zipcodes WHERE zipcode = '90210') , earth_coords)/1609.344 AS RADIUS FROM pets

Re: [PERFORM] cube operations slower than geo_distance() on production server

2007-02-13 Thread Merlin Moncure
On 2/13/07, Merlin Moncure [EMAIL PROTECTED] wrote: On 2/12/07, Mark Stosberg [EMAIL PROTECTED] wrote: Merlin Moncure wrote: Here the basic query I'm using: SELECT -- 1609.344 is a constant for meters per mile cube_distance( (SELECT earth_coords from zipcodes WHERE zipcode =

[PERFORM] Question about Bitmap Heap Scan/BitmapAnd

2007-02-13 Thread Guillaume Smet
Hi all, I'm currently working on optimizing a couple of queries. While studying the EXPLAIN ANALYZE output of a query, I found this Bitmap Heap Scan node: - Bitmap Heap Scan on lieu l (cost=12.46..63.98 rows=53 width=94) (actual time=35.569..97.166 rows=78 loops=1) Recheck Cond:

Re: [PERFORM] Question about Bitmap Heap Scan/BitmapAnd

2007-02-13 Thread Tom Lane
Guillaume Smet [EMAIL PROTECTED] writes: What surprises me is that parking is in the filter and not in the Recheck Cond whereas it's part of the second Bitmap Index Scan of the Bitmap And node. That's probably because of this: /* * When dealing with special or lossy operators, we

[PERFORM] Proximity query with GIST and row estimation

2007-02-13 Thread Guillaume Smet
Hi all, Following the work on Mark Stosberg on this list (thanks Mark!), I optimized our slow proximity queries by using cube, earthdistance (shipped with contrib) and a gist index. The result is globally very interesting apart for a specific query and we'd like to be able to fix it too to be

Re: [PERFORM] Question about Bitmap Heap Scan/BitmapAnd

2007-02-13 Thread Guillaume Smet
On 2/13/07, Tom Lane [EMAIL PROTECTED] wrote: bitmapqualorig = list_difference_ptr(bitmapqualorig, qpqual); What's not immediately clear is why the condition was in both lists to start with. Perhaps idx_lieu_parking is a partial index with this as its WHERE condition? Yes, it is:

Re: [PERFORM] Question about Bitmap Heap Scan/BitmapAnd

2007-02-13 Thread Tom Lane
Guillaume Smet [EMAIL PROTECTED] writes: So the basic explanation is that it's in both lists due to the partial index and only qpqual keeps the condition? I would have expected the opposite but it doesn't change anything I suppose? It gets the right answer, yes. I'm not sure if we could

Re: [PERFORM] CPU Usage

2007-02-13 Thread Alan Hodgson
On Tuesday 13 February 2007 10:36, Campbell, Lance [EMAIL PROTECTED] wrote: We have 12+ schemas in 1 database. When I do a unix top command I notice one postmaster process has 100% CPU usage. This process just stays at 100% to 99% CPU usage. There are other postmaster processes that pop up.

[PERFORM] JOIN to a VIEW makes a real slow query

2007-02-13 Thread Chuck D.
Hi folks, I don't know if this is an SQL or PERFORMANCE list problem but I wanted to check here first. I've seen this discussed on the list before but I'm still not sure of the solution. Maybe my query is just structured wrong. I recently visited an old project of mine that has a 'city',

Re: [PERFORM] JOIN to a VIEW makes a real slow query

2007-02-13 Thread Merlin Moncure
On 2/13/07, Chuck D. [EMAIL PROTECTED] wrote: Hi folks, I don't know if this is an SQL or PERFORMANCE list problem but I wanted to check here first. I've seen this discussed on the list before but I'm still not sure of the solution. Maybe my query is just structured wrong. I recently visited

[PERFORM] quad or dual core Intel CPUs

2007-02-13 Thread Kenji Morishige
I am about to pull the trigger on a new machine after analyzing some discussions I posted here last year. I've been trying to spec out a reliable and powerfull enough machine where I won't have to replace it for some time. Currently I've been using a dual Xeon 3.06ghz with 4GB of ram and

Re: [PERFORM] JOIN to a VIEW makes a real slow query

2007-02-13 Thread Chuck D.
On Tuesday 13 February 2007 13:16, Merlin Moncure wrote: use 'union all' instead of union. union without all has an implied sort and duplicate removal step that has to be resolved, materializing the view, before you can join to it. Thanks for that Merlin, I forgot about using ALL. That

Re: [PERFORM] JOIN to a VIEW makes a real slow query

2007-02-13 Thread Tom Lane
Chuck D. [EMAIL PROTECTED] writes: It is still using that sequence scan on the view after the APPEND for the us_city and world_city table. Any reason why the view won't use the indexes when it is JOINed to another table but it will when the view is queried without a JOIN? I should have

Re: [PERFORM] quad or dual core Intel CPUs

2007-02-13 Thread Arjen van der Meijden
Hi Kenji, On 13-2-2007 20:46 Kenji Morishige wrote: Here is the full specification of the new box I hope to build and run FreeBSD 6.X and PostgreSQL on: - SuperMicro Dual Xeon X7DBE+ motherboard + 2 x Quad Core X5355 2.66Ghz OR + 2 x Dual Core 5160 3.0Ghz - 8 x 1GB PC2-4200 fully

Re: [PERFORM] quad or dual core Intel CPUs

2007-02-13 Thread Mark Kirkwood
Kenji Morishige wrote: Please comment on any issues you may see with this box and my assumptions. Also any FreeBSD kernel issues or tweaks you could recommend. I would recommend posting to freebsd-hardware or freebsd-stable and asking if there are any gotchas with the X7DBE+ and 6.2 (for

Re: [PERFORM] quad or dual core Intel CPUs

2007-02-13 Thread Dan Harris
Arjen van der Meijden wrote: But be aware that there can be substantial and unexpected differences on this relatively new platform due to simply changing the OS, like we saw when going from linux 2.6.15 to 2.6.18, as you can see here: http://tweakers.net/reviews/657/2 Having upgraded to

Re: [PERFORM] quad or dual core Intel CPUs

2007-02-13 Thread Guillaume Smet
Dan, On 2/13/07, Dan Harris [EMAIL PROTECTED] wrote: Having upgraded to 2.6.18 fairly recently, I am *very* interested in what caused the throughput to drop in 2.6.18? I haven't done any benchmarking on my system to know if it affected my usage pattern negatively, but I am curious if anyone