Re: PostgreSQL crashes with Qmail-SQL

On Fri, Jan 25, 2002 at 10:20:01AM +0100, Michael Devogelaere wrote:
> I've rerun the tests and got:
> NOTICE:     Message from PostgreSQL backend:
>     The Postmaster has informed me that some other backend died abnormally
> and possibly corrupted shared memory.
>     I have rolled back the current transaction and am going to terminate
> your database system connection and exit.
>     Please reconnect to the database system and repeat your query.
> 
> Nothing showed up in the logs however. This time i aborted the test after the
> first errormessages and could reconnect to the database ! I don't know if this 
> has to do with the number of <defunct> postmasters: there only showed up 2 now 
> and not a few screens as in the first crash. When typing 'ps aux' a few minutes
> later they were all gone !

I know nothing about the reasons of your crash, if the message given
above suffices to determine the reason and how to configure the
database to get more reasonable log messages (actually about the last
point I know something, but you can read it at

* http://developer.postgresql.org/docs/postgres/install-procedure.html
* http://developer.postgresql.org/docs/postgres/runtime-config.html#LOGGING

so I won't repeat that stuff here), but I know that for scenarios like
yours connection pooling was invented. Connection pooling avoids the
creation of a new backend process for each single query. Did you ever
try your test with connection pooling ? Real databases *require*
connection pooling in such a case, MySQL or file systems
don't. (Actually when considering to use MySQL, why not using
ReiserFS. It's also kind of a database with hashs and all this stuff ;-)

I know that another mail in this thread already mentioned connection
pooling, but I don't remember any answer from your side. Maybe it's
worth an attempt.

-- 
Holger Krug
hkrug@rationalizer.com