Re: [GENERAL] Postgres benchmark?

2008-07-07 Thread Greg Smith

On Wed, 2 Jul 2008, David Siebert wrote:

What I would like to try just for my own amusment is to build a small 
test box. It will not be a server class machine. I am thinking of using 
an AMD X2 and to start a SATA hard drive.


What I did when wanting to run similar experiments was get a moderately 
expensive RAID controller (Areca ARC-1210, about $300, there are other 
options) and step up to 3 drives--DB, WAL, and OS (two more cheap ATA 
drives will set you back another $120).  That's just enough to get you 
benchmark results that translate fairly well to server land.  If you don't 
don't have a controller with a decent write cache on it, there are all 
kinds of write-heavy tests that you can't get results that mean anything 
useful on.



Then I would like to test different file systems, then different
operating systems, different amounts of ram, 32 vs 64 bit, and software
raids.


Different operating systems is the hard one here.  My own tests trying to 
compare Linux and Solaris on the same hardware gave very different 
results, and it's a lot of work to get a fair comparison between two 
platforms like that.  A lot of that is not being able to use the same 
filesystem in the same way; UFS/ZFS are tuned very differently from ext3 
for example.


When you run database benchmarks, the usual setup is to note what ratio 
there is between the database and the amount of RAM, because varying the 
RAM itself is kind of boring.  You end up with a curve like 
http://www.westnet.com/~gsmith/content/postgresql/pgbench-scaling.htm 
regardless, how much RAM you have just shifts exactly where the inflection 
points are in an unsurprising way.


32/64, file systems, and software RAID are a bit more useful.  A lot of 
the filesystem/RAID ground has been explored at these two links: 
http://www.commandprompt.com/blogs/joshua_drake/2008/04/is_that_performance_i_smell_ext2_vs_ext3_on_50_spindles_testing_for_postgresql/ 
http://merlinmoncure.blogspot.com/2007/08/following-are-results-of-our-testing-of.html



I doubt that would ever publish my results. The flame war that would
happen would take all the fun out of it for me. I am sure that someone
would say that since I wasn't using a server machine that my results
where invalid, others would say that I made errors in tuning for the
different operating systems or that X would show benefits if I was using
a real server machine.


What you should do is send out your suggested test plan before you run the 
tests and get feedback such that you're more likely to get accurate 
results.  There's a lot of useful tests that could be done in this area 
that are not too hard to design, but the actual follow-through takes a 
long time.  If you wanted to do some of that work, you should be able to 
get enough help doing that to end up with worthwhile results in the end.


--
* Greg Smith [EMAIL PROTECTED] http://www.gregsmith.com Baltimore, MD

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Re: [GENERAL] Postgres benchmark?

2008-07-02 Thread David Siebert

Well that is the rub. I am currently using Postgres everyday. It runs
like a champ and even on an old PIII 600 MHZ machine with a single old
and slow IDE drive and 256 megs of ram it is fast enough for what we do.
This is more for me to do some testing with.
I think it would useful as a tunning tool if nothing else.
What I would like to try just for my own amusment is to build a small
test box. It will not be a server class machine. I am thinking of using
an AMD X2 and to start a SATA hard drive.
Then I would like to test different file systems, then different
operating systems, different amounts of ram, 32 vs 64 bit, and software
raids.
I would use the same machine for all the tests so it would have a good
base line.
I doubt that would ever publish my results. The flame war that would
happen would take all the fun out of it for me. I am sure that someone
would say that since I wasn't using a server machine that my results
where invalid, others would say that I made errors in tuning for the
different operating systems or that X would show benefits if I was using
a real server machine. And all of them may be right.
But sometimes you just want to play.




Do you want to use PostgreSQL for any particular task? If so, the best 
benchmark is probably one that simulates your specific workload. 
Comparing generic benchmark results like pgbench etc may not usefully 
reflect performance in real-world use with your load and your data.


--
Craig Ringer





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Re: [GENERAL] Postgres benchmark?

2008-07-02 Thread Mayuresh Nirhali

Craig Ringer wrote:

David Siebert wrote:

I am interesting in finding a good Postgres benchmark. I an not
interested in seeing how fast Postgres is compared to MySql, Firebird,
or any other SQL database.
What I am interested in is how file systems, memory, and X-64 vs X-32
effects the performance of Postgres.
It is more for my own curiosity to be honest. Right now Postgres is more
than fast enough for what I am doing.


Do you want to use PostgreSQL for any particular task? If so, the best 
benchmark is probably one that simulates your specific workload. 
Comparing generic benchmark results like pgbench etc may not usefully 
reflect performance in real-world use with your load and your data.

and If you are running Solaris/OpenSolaris, DTrace is your friend.

Mayuresh


--
Craig Ringer




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Re: [GENERAL] Postgres benchmark?

2008-07-02 Thread Craig Ringer

David Siebert wrote:

I am interesting in finding a good Postgres benchmark. I an not
interested in seeing how fast Postgres is compared to MySql, Firebird,
or any other SQL database.
What I am interested in is how file systems, memory, and X-64 vs X-32
effects the performance of Postgres.
It is more for my own curiosity to be honest. Right now Postgres is more
than fast enough for what I am doing.


Do you want to use PostgreSQL for any particular task? If so, the best 
benchmark is probably one that simulates your specific workload. 
Comparing generic benchmark results like pgbench etc may not usefully 
reflect performance in real-world use with your load and your data.


--
Craig Ringer

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[GENERAL] Postgres benchmark?

2008-07-02 Thread David Siebert

I am interesting in finding a good Postgres benchmark. I an not
interested in seeing how fast Postgres is compared to MySql, Firebird,
or any other SQL database.
What I am interested in is how file systems, memory, and X-64 vs X-32
effects the performance of Postgres.
It is more for my own curiosity to be honest. Right now Postgres is more
than fast enough for what I am doing.


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[GENERAL] Postgres Benchmark

2001-02-16 Thread Jreniz

Hello!!

I need demostrate that PostgreSQL is a great RDBMS for my undergraduate
project, because this, Does somebody has a bechmark (or similar
document) between Postgres and others DB (commercial DB's, principally)?

Thanks in advance!!