Setup GnuCash Postgresql

[HerSam]

Hi All,
I am realy new user of GnuCash.
Is any one can inform me to setup Gnucash link with Postgresql.
I run RH9, with GnuCash (ver 1.8.1) and Gnucash-Backend-Postgres installed,
and I have setup my Postgresql and it running (Postgres 7.3).

But when i running GnuCash, it just configured for store data in local file
not in Postgresql database.

I could not find any setup option in GnuCash to set any connection to Postgresql.

Thanks for Help.

Rgds
HerSam