Re: BUG #4919: CREATE USER command slows down system performance

Lauris Ulmanis wrote:
> Hello again!
>
> I did test on my local test server
>
> I created up 500 000 users in function loop very quickly - within 48
> seconds. I did again this script reaching up to 1 billion users - results
> was the same - 48 seconds. It is very quickly.
>
> But problem seems is with transaction preparation because if in database is
> 1 billion users and I want to create 1 new - it will take 4 seconds!
>
> After that I generated up to 2 billion users in this server (generation
> process took just 1.44 minutes of times - again quickly).
>
> And did 1 user creation again - now it took 9 seconds of time!
>
> What is a reason of this slowness? Is there a workaround or solution how to
> avoid it?

My bet is on the pg_auth flat file. I doubt we have ever tested the
behavior of that code with 1 billion users ...

Do you really need 1 billion users? Are you planning on giving accounts
to every human being in the planet or what? I mean, what's the point of
this test?

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.