postgresql conf on postgres 8.4

Postgre config file locations
http://www.postgresql.org/docs/8.4/static/runtime-config-file-locations.html

18.2. File Locations

In addition to the postgresql.conf file already mentioned, PostgreSQL uses two other manually-edited configuration files, which control client authentication (their use is discussed in Chapter 19). By default, all three configuration files are stored in the database cluster's data directory. The parameters described in this section allow the configuration files to be placed elsewhere. (Doing so can ease administration. In particular it is often easier to ensure that the configuration files are properly backed-up when they are kept separate.)

data_directory (string)

Specifies the directory to use for data storage. This parameter can only be set at server start.

config_file (string)

Specifies the main server configuration file (customarily called postgresql.conf). This parameter can only be set on the postgres command line.

hba_file (string)

Specifies the configuration file for host-based authentication (customarily called pg_hba.conf). This parameter can only be set at server start.

ident_file (string)

Specifies the configuration file for Section 19.2 username mapping (customarily called pg_ident.conf). This parameter can only be set at server start.

external_pid_file (string)

Specifies the name of an additional process-id (PID) file that the server should create for use by server administration programs. This parameter can only be set at server start.

In a default installation, none of the above parameters are set explicitly. Instead, the data directory is specified by the -D command-line option or the PGDATA environment variable, and the configuration files are all found within the data directory.

http://www.postgresql.org/docs/8.4/static/runtime-config-connection.html