The terms "PostgreSQL" and "Postgres" will be used interchangeably to refer to the software that accompanies this documentation.
An administrator is generally a person who is in charge of installing and running the server. A user could be anyone who is using, or wants to use, any part of the PostgreSQL system. These terms should not be interpreted too narrowly; this documentation set does not have fixed presumptions about system administration procedures.
We use /usr/local/pgsql/ as the root directory of the installation and /usr/local/pgsql/data as the directory with the database files. These directories may vary on your site, details can be derived in the Administrator's Guide.
In a command synopsis, brackets ([ and ]) indicate an optional phrase or keyword. Anything in braces ({ and }) and containing vertical bars (|) indicates that you must choose one alternative.
Examples will show commands executed from various accounts and programs. Commands executed from a Unix shell may be preceded with a dollar sign ("$"). Commands executed from particular user accounts such as root or postgres are specially flagged and explained. SQL commands may be preceded with "=>" or will have no leading prompt, depending on the context.
Note: The notation for flagging commands is not universally consistent throughout the documentation set. Please report problems to the documentation mailing list <pgsql-docs@postgresql.org>.