Appendix D. Internal psql Variables
The psql client uses a variety of internal variables as special system
variables to control aspects of the program. A few of the most notable variables are PROMPT1, PROMPT2, and PROMPT3, which store the
prompts for the program. While running the program you can set and unset these variables at will
using the \set and \unset commands. A list of all the
special variables psql uses follows:
DBNAMEThis variable holds the name of the database psql is currently connected to. This variable is set whenever psql connects to a database, either when starting up or when instructed to connect during program operation.
ECHOThis variable controls what gets displayed on the screen when executing commands from a file. To display all contents of a script file on the screen as it is parsed, set this variable to all. To display all queries as they are sent to the backend process, set this variable to queries.
ECHO_HIDDENThis variable, when set to true, displays the queries used by slash commands from within psql. Such queries will be displayed before they are sent to the backend. To show the queries for slash commands without actually executing them, set
ECHO_HIDDENto noexec.ENCODINGThis variable holds the database’s multibyte encoding scheme. You must have compiled PostgreSQL to support multibyte encoding; if you did not, this variable will contain SQL_ASCII.
HISTCONTROLThis variable sets methods of controlling the psql history buffer. Set this variable to ignorespace ...