[Pljava-dev] Using the $DATADIR variable within postgresql.conf

Eric E wrote:
> Hi all,
> I'm trying to set up PL/JAVA in a flexible way based on the mount
> point of my data for postgres. I'd like to have to
> dynamic_library_path point to $DATADIR/pljava, where $DATADIR the data
> directory of postgres (the directory containing postgresql.conf and
> pg_hba.conf). That way I can just mount the postgres data onto a
> mount point, point the postmaster to the right place, and have PL/JAVA
> ready to roll with the database. This type of flexibility becomes
> particularly relevant with Xen images...
>
> The problem is that I don't know how to reference the $DATADIR
> environment variable from with postgresql.conf. I've tried $DATADIR,
> $datadir, $data_directory (which apparently must be hard-set at the
> top of postgresql.conf ), ${DATADIR}, {$DATADIR}, etc. I always get
> the same message in the deployer:
> ERROR: invalid macro name in dynamic library path:
> $libdir;{$DATADIR}/pljava
>
> Does anyone have any ideas how to do this?
>
You cannot use environment variables in postgresql.conf. You can
however, pass configuration settings on the command line when you start
the postmaster. See
http://www.postgresql.org/docs/8.1/interactive/runtime-config.html for
more info.

Kind Regards,
Thomas Hallgren