Re: ORA-12500: TNS:listener failed to start a dedicated server process

Brijesh wrote:
> Hi Everyone
>
> I am running Oracle 9i Release 9.0.1 on Windows 2000 Server. Last
> night, I started getting the error ORA-12500: TNS:listener failed to
> start a dedicated server process.

This is one of the Oracle Server error messages that can mean almost everything. It is a generic error, the some goes for ORA-03113 end-of-file on communication channel and there are others. ORA-12500 is telling you only that for whatever reason your listener was unable to start a server process for a new connection. Common reasons are:

1. OS problems - unstable environment
2. DB limits - processes DB parameter too low as mentioned by Sybrand
3. OS limits - semaphores, ulimits, too many processes already running
4. not enough resources - memory full, swap full, etc.

You have to check the secondary OS message that should be accompanying ORA-12500 and also check OS logs (syslog, security logs, etc.). Also if there is any security software installed (firewall, E-Trust Access Control) you should also check their logs (especially denied operations log).
As summary: according to my experiences 90+% of ORA-12500 related problems had origin outside of a database that was suffering from them.

--
Dusan Bolek