$PGDATA/pg_ident.con, $PGDATA/pg_hba.conf, $PGDATA/postgresql.conf The PGDATA environment variable is used to distinguish database clusters from one another by setting it to the value of the directory which contains the cluster desired. The three configuration files exist in every PGDATA/ directory. Details on the format of the files and the options that can be set in each can be found in . Install the /etc/rc.d/init.d/postgresql init script included in the package. make install-postgresql