System Configuration Files
This is the configuration file that specifies what options are to be used when the server is started as postmaster. The name of this file has changed between versions and will either be called pg_options, postmaster.opts, or postgresql.conf, depending on your current version. The exact syntax and options available within this configuration file also vary depending on the version.
Essentially, this file is a text file that contains various command-line switches. A standard configuration file might appear as follows:
-p 5432 →Use TCP/IP port 5432 -D /usr/local/pgsql/data/ →Path to data directory -B 64 →Start with 64 8KB buffers -b /usr/local/pgsql/bin/postgres ...