SHOW will display the current setting of run-time parameters. These variables can be set using the SET statement, by editing the postgresql.conf configuration file, through the PGOPTIONS environmental variable (when using libpq or a libpq-based application), or through command-line flags when starting the postgres server. See Chapter 19 for details.
The name of a run-time parameter. Available parameters are documented in Chapter 19 and on the SET reference page. In addition, there are a few parameters that can be shown but not set:
Shows the server's version number.
Shows the server-side character set encoding. At present, this parameter can be shown but not set, because the encoding is determined at database creation time.
Shows the database's locale setting for collation (text ordering). At present, this parameter can be shown but not set, because the setting is determined at database creation time.
Shows the database's locale setting for character classification. At present, this parameter can be shown but not set, because the setting is determined at database creation time.
True if the current role has superuser privileges.
Show the values of all configuration parameters, with descriptions.
The function current_setting produces equivalent output; see Section 9.26. Also, the pg_settings system view produces the same information.
Show the current setting of the parameter DateStyle:
SHOW DateStyle; DateStyle ----------- ISO, MDY (1 row)
Show the current setting of the parameter geqo:
SHOW geqo; geqo ------ on (1 row)
Show all settings:
SHOW ALL;
name | setting | description
-------------------------+---------+-------------------------------------------------
allow_system_table_mods | off | Allows modifications of the structure of ...
.
.
.
xmloption | content | Sets whether XML data in implicit parsing ...
zero_damaged_pages | off | Continues processing past damaged page headers.
(196 rows)