Contents
current_setting()
current_setting() is a system function returning the current value of a configuration parameter and certain other values.
current_setting() was added in PostgreSQL 7.3.
Usage
current_setting ( setting_name text [, missing_ok boolean ] ) → text
Similar to the SHOW command, current_setting() returns the current value of a configuration parameter (and certain other parameters). However in contrast to SHOW, current_setting() is a normal function and can be combined with other SQL elements. Additionally, it can display custom variables, and can optionally be executed without returning an error if the specified configuration parameter does not exist.
Like SHOW, current_setting() can also display whether the current user is a superuser via the pseudo-parameter is_superuser.
The system catalog view pg_settings can also be used to retrieve information about the current value of configuration parameters.
Change history
- PostgreSQL 9.6
- option
missing_okadded (commit 10fb48d6)
- option
- PostgreSQL 7.3
- added (commit 7ef56347)
Examples
Retrieve a normal configuration parameter:
postgres=# SELECT current_setting('port');
current_setting
-----------------
5432
(1 row)
Attempt to retrieve a configuration parameter which does not exist:
postgres=# SELECT current_setting('foo');
ERROR: unrecognized configuration parameter "foo"
Safely attempt to retrieve a configuration parameter which might not exist (PostgreSQL 9.6 and later):
postgres=# SELECT current_setting('foo', true);
current_setting
-----------------
(1 row)
Display whether the current user is a superuser:
postgres=# SELECT current_setting('is_superuser');
current_setting
-----------------
on
(1 row)
References
- PostgreSQL documentation: Configuration Settings Functions