SHOW
SHOW — show the value of a run-time parameter
Synopsis
SHOW name
SHOW ALL
Description
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. 
Parameters
- name
- 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: - SERVER_VERSION
- Shows the server's version number. 
- SERVER_ENCODING
- 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. 
- LC_COLLATE
- 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. 
- LC_CTYPE
- 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. 
- IS_SUPERUSER
- True if the current role has superuser privileges. 
 
- ALL
- Show the values of all configuration parameters, with descriptions. 
Notes
 The function current_setting produces equivalent output; see Section 9.26. Also, the pg_settings system view produces the same information. 
Examples
 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)
Compatibility
 The SHOW command is a Postgres Pro extension.