Re: [PERFORM] SELECT INTO large FKyed table is slow

2010-12-02 Thread Mario Splivalo

On 12/01/2010 10:43 PM, Pierre C wrote:

On Wed, 01 Dec 2010 18:24:35 +0100, Kevin Grittner
kevin.gritt...@wicourts.gov wrote:


Mladen Gogala mladen.gog...@vmsinfo.com wrote:


There is a operating system which comes with a very decent extent
based file system and a defragmentation tool, included in the OS.
The file system is called NTFS

Been there, done that. Not only was performance quite poor compared
to Linux, but reliability and staff time to manage things suffered
in comparison to Linux.


Please don't start with NTFS. It is the worst excuse for a filesystem
I've ever seen.


It is OT, but, could you please shead just some light on that? Part of 
my next project is to test performance of pg9 on both windows and linux 
systems so I'd appreciate any data/info you both may have.


Mario

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Re: [PERFORM] SELECT INTO large FKyed table is slow

2010-12-02 Thread Kevin Grittner
Mario Splivalo mario.spliv...@megafon.hr wrote:
 
 It is OT, but, could you please shead just some light on that?
 Part of my next project is to test performance of pg9 on both
 windows and linux systems so I'd appreciate any data/info you both
 may have.
 
I don't know how much was the filesystem, but with both tuned to the
best of our ability Linux on xfs ran much faster than Windows on
NTFS.  The lack of atomic operations and a lockfile utility on
Windows/NTFS was something of a handicap.  I have found Linux to be
much more reliable and (once I got my bash scripting knowledge of
common Linux utilities to a certain level), much easier to
administer.  Getting my head around xargs was, I think, the tipping
point.  ;-)
 
-Kevin

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[PERFORM] Multicore Postgres 9.0.1 issue - single transaction problem.

2010-12-02 Thread Piotr Czekalski

Hello Postgres Users.

Last days I've installed and configured new x64 release of PostgreSQL 
running Windows 2008 R2 with dual XEON 5530 processors (2x4xHT = 16 
working units). Previously the database was running on Fedora 12 x86_64 
under Microsoft hypervisor (HyperV) thus because of the network card 
driver limitation there was only one core available.


The problem I'm facing is a very long, single transaction lasting about 
12hours or even more (as it doesn't exist Pragma Autonomous Transaction 
like Oracle has) that consist of tones of PLPGSQL code, processing a lot 
of data, causing huge CPU load and disk drive transfers.
When moved to the x64 system as described above, the shared memory size 
is not a problem anymore, the disk channel is running very smoothly, the 
only suprising think is that the transaction above utilizes only one 
core of the machine - is it possible to parallelize it without rewriting 
all the code from scratch?


Is there any configuration parameter limiting number of CPUs? The 
release is a standard/public x64 binary of PostgreSQL 9.0.1, taken 
following official site.


Thanks in advance for any help.

Piotr Czekalski

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Re: [PERFORM] Multicore Postgres 9.0.1 issue - single transaction problem.

2010-12-02 Thread Scott Marlowe
On Thu, Dec 2, 2010 at 2:04 PM, Piotr Czekalski pczekal...@techbaza.pl wrote:
 Hello Postgres Users.

 Last days I've installed and configured new x64 release of PostgreSQL
 running Windows 2008 R2 with dual XEON 5530 processors (2x4xHT = 16 working
 units). Previously the database was running on Fedora 12 x86_64 under
 Microsoft hypervisor (HyperV) thus because of the network card driver
 limitation there was only one core available.

 The problem I'm facing is a very long, single transaction lasting about
 12hours or even more (as it doesn't exist Pragma Autonomous Transaction like
 Oracle has) that consist of tones of PLPGSQL code, processing a lot of data,
 causing huge CPU load and disk drive transfers.
 When moved to the x64 system as described above, the shared memory size is
 not a problem anymore, the disk channel is running very smoothly, the only
 suprising think is that the transaction above utilizes only one core of the
 machine - is it possible to parallelize it without rewriting all the code
 from scratch?

A single connection uses a single CPU.  While there's been some talk
of parallelizing some part of pgsql, nothing I know of has been done.

Is it possible you're doing parts in plpgsql that should really be
done externally / with a batch processing system or hadoop or
something?

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