Re: pg locking problem

> When running a test with multiple (>=2) users pg 'seizes up' after a
> few transactions. Cpu goes 100% and disk goes to 0%. This lasts
> 'forever' (overnight)On the same test all other tested databases don't
> have this problem.
> 
> The error occurs with higher tx rate, when transactions bump into each
> other more frequently. Some 'deadlock detected' messages appear around
> the hang up time, but _not_ always.
> 
> Occasionally - but rarely - the seizure looks differently. CPU goes to
> 0%, disk goes to 0% and, after about one minute, the processing is
> resumed.
> 
> The current suspicion is that it is due to difference in lock and
> deadlock handling between pg and most other dbs. In general I found
> that I can't set transaction isolation level to READ_UNCOMMITTED (as
> for other databases), the lowest level is READ_COMMITEED.
> 
> Any ideas how to reduce this problem? I really want to prove pg perf
> with 20-100 users and have a problem running 2...

Have you ever tried the test on UNIX (or UNIX like systems)? I have
never seen such a problem with PostgreSQL running on UNIX. Also I
think PostgreSQL on Win is not ready for practical use...

> It wouldn't be fair (to other db's) to rewrite the test with some
> pg-only LOCK command etc. I suspect I'm missing something simple, like
> one of .conf parameters.
> 
> 
> P.S. Using WinNT/Win2K system, pg 7.1.3 (current cygwin), jdbc driver
> is jdbc7.1-1.3, cygipc is 1.10-1, java is 1.3.1_01a (current jdk).
> Default pg installation, except for bumped up memory and 8 wal files.
> 
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