Re: Benchmark

Nikolaj Lundsgaard wrote:
> Is there anywhere I can find some benchmark test for postgres. The reason is that I want to use it for a site that could have several simultanous users querying the database and I want to be sure that it is stable (and fast) enough to handle that kind of (ab)use.

There is actually no (DB-independant) benchmark suite
publicly available.

>
> Also which is fastest ?
>
> 1. A query (using index of course) for a text in the database.
>
> or
>
> 2. Reading from a file on the harddisk.
>
>
> If the answer is 1 will the answer still be 1 if I do it several times (100.000+ a day)

Since any DB access boils down somehow to file access, it
could never be 1 (as long as your solution doesn't need to
sequentially read big files to find small pieces of
information).

The question you have to ask is, what would happen in a
concurrent environment? If there's at least one writing
process, must the entire information be blocked from reading?

Postgres uses MVCC (Multi Version Concurrency Control) for
it. So no reader will ever be blocked by a writer - it simply
sees a snapshot of the entire data as it was when he executed
the first DML statement.

If you have total static data, that never changes during
uptime of your application, use flat files or some higher
level file interface like GDB or MySQL.

If you have data in motion, use a database.

Jan

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