Обсуждение: Projecting currentdb to more users

Hi,


We have a couple of database that are identical (one for each
customer).

They are all relatively small, ranging from 100k records to 1m records.

There's only one main table with some smaller tables, a lot of indexes
and some functions.


I would like to make an estimation of the performance, the diskspace
and other related things,

when we have database of for instance 10 million records or 100
million records.


Is there any math to be done on that ?


Met vriendelijke groeten,

Bien à vous,

Kind regards,


<bold>Yves Vindevogel</bold>

<bold>Implements</bold>

<smaller>

</smaller>Hi,

We have a couple of database that are identical (one for each customer).
They are all relatively small, ranging from 100k records to 1m records.
There's only one main table with some smaller tables, a lot of indexes
and some functions.

I would like to make an estimation of the performance, the diskspace
and other related things,
when we have database of for instance 10 million records or 100 million
records.

Is there any math to be done on that ?

Met vriendelijke groeten,
Bien à vous,
Kind regards,

Yves Vindevogel
Implements

<smaller>


Mail: yves.vindevogel@implements.be  - Mobile: +32 (478) 80 82 91


Kempische Steenweg 206 - 3500 Hasselt - Tel-Fax: +32 (11) 43 55 76


Web: http://www.implements.be

<italic><x-tad-smaller>

First they ignore you.  Then they laugh at you.  Then they fight you.
Then you win.

Mahatma Ghandi.</x-tad-smaller></italic></smaller>


Mail: yves.vindevogel@implements.be  - Mobile: +32 (478) 80 82 91

Kempische Steenweg 206 - 3500 Hasselt - Tel-Fax: +32 (11) 43 55 76

Web: http://www.implements.be

First they ignore you.  Then they laugh at you.  Then they fight you.
Then you win.
Mahatma Ghandi.

On 7/12/05, Yves Vindevogel <yves.vindevogel@implements.be> wrote:
> Hi,
>
> We have a couple of database that are identical (one for each customer).
> They are all relatively small, ranging from 100k records to 1m records.
> There's only one main table with some smaller tables, a lot of indexes
> and some functions.
>
> I would like to make an estimation of the performance, the diskspace
> and other related things,
> when we have database of for instance 10 million records or 100 million
> records.
>
> Is there any math to be done on that ?

Its pretty easy to make a database run fast with only a few thousand
records, or even a million records, however things start to slow down
non-linearly when the database grows too big to fit in RAM.

I'm not a guru, but my attempts to do this have not been very accurate.

Maybe (just maybe) you could get an idea by disabling the OS cache on
the file system(s) holding the database and then somehow fragmenting
the drive severly (maybe by putting each table in it's own disk
partition?!?) and measuring performance.

On the positive side, there are a lot of wise people on this list who
have +++ experience optimzing slow queries on big databases. So
queries now that run in 20 ms but slow down to 7 seconds when your
tables grow will likely benefit from optimizing.
--
Matthew Nuzum
www.bearfruit.org

From AMD's suit against Intel. Perhaps relevant to some PG/AMD issues.

"...125. Intel has designed its compiler purposely to degrade performance when a program
is run on an AMD platform. To achieve this, Intel designed the compiler to compile code
along several alternate code paths. Some paths are executed when the program runs on an Intel
platform and others are executed when the program is operated on a computer with an AMD
microprocessor. (The choice of code path is determined when the program is started, using a
feature known as "CPUID" which identifies the computer's microprocessor.) By design, the
code paths were not created equally. If the program detects a "Genuine Intel" microprocessor,
it executes a fully optimized code path and operates with the maximum efficiency. However,
if the program detects an "Authentic AMD" microprocessor, it executes a different code path
that will degrade the program's performance or cause it to crash..."

2005/7/12, Mohan, Ross <RMohan@arbinet.com>:
> From AMD's suit against Intel. Perhaps relevant to some PG/AMD issues.

Postgres is compiled with gnu compiler. Isn't it ?
I don't know how much can Postgres benefit from an optimized Intel compiler.

--
Jean-Max Reymond
CKR Solutions Open Source
Nice France
http://www.ckr-solutions.com