Re: Zombie processes

Peterson, Bjorn wrote:
>
> I am running Postgres 8.0.1 on a Windows 2000 server as a service, and the
> query returns appropriate values after about 30 seconds when executed from a
> psql console.  However, when running this query from a Java application on
> the same machine through the postgres JDBC driver, the Java app hangs on
> st.executeQuery().  The query shows up in pg_stat_activity for about 3
> minutes then goes away, but the process referenced by the pg_stat_activity
> remains active and consumes 50% of the CPU resources indefinitely until I
> kill it off.  I let it run for over an hour yesterday.  I can reproduce this
> every time I run this query.

Two things you should start with:
1. Turn query-logging on in your postgresql.conf so we can see exactly
what is happening
2. See if you can simulate this using PREPARE/EXECUTE for the query.

I'm guessing that the Java side of things is producing a prepared query
and substituting parameters in. That might produce a different plan.

First thing is to turn query logging on though, that way you can check
exactly what is being executed.
--
   Richard Huxton
   Archonet Ltd