Re: per user/database connections limit again

Bruce Momjian wrote:

>I removed your use of the pg_auth flat file. By the time you have the
>PROC entry to do your lookups, you might as well just use the system
>cache.
>
>There is a race condition in the code because we set our PROC entry
>before we check for other entries. If there is one connection left and
>two backends do this at the same time, they would both fail, while one
>should fail and the other succeed. Without a lock, I see no way to avoid
>it so I just commented it in the code.
>
>
Yeah my working version was doing this too but I wanted to avoid lock on
PROC array and that race condition and because pg_auth is loaded anyway
I used it.

>Also, I felt that zero should mean allow no/zero connections, rather
>than representing unlimited connections. I used -1 for unlimited. We
>can either document the use of -1, or add syntax to allow NO CONNECTION
>LIMIT, or something like that.
>
>
Right, maybe we could remove datallowconn from pg_database (in future)
if we can achieve same thing using datconnlimit = 0 ?

>The patch requires a catalog version update when applied.
>
>
Yes, thanks for your work on this patch, I will write documentation for
it in next few days.

--
Regards
Petr Jelinek (PJMODOS)