SHOW — show the value of a run-time parameter
SHOWnameSHOW ALL SHOWname%SHOW%nameSHOW%name%
SHOW will display the current setting of
run-time parameters. These variables can be set using the
SET statement, by editing the
lightdb.conf configuration file, through
the LTOPTIONS environmental variable (when using
libpq or a libpq-based
application), or through command-line flags when starting the
lightdb server. See Chapter 18 for details.
nameThe name of a run-time parameter. Available parameters are documented in Chapter 18 and on the SET reference page. In addition, there are a few parameters that can be shown but not set:
SERVER_VERSIONShows the server's version number.
LIGHTDB_SERVER_VERSIONShows the LightDB server's version number.
LIGHTDB_SERVER_VERSION_NUM
Shows the LightDB server's version number, value is major_version * 10000 + minor_version * 100.
SERVER_ENCODINGShows 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_COLLATEShows 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_CTYPEShows 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_SUPERUSERTrue if the current role has superuser privileges.
ALLShow the values of all configuration parameters, with descriptions.
name%Show the values of all configuration parameters beginning with name, with descriptions.
%nameShow the values of all configuration parameters ending with name, with descriptions.
%name%Show the values of all configuration parameters including with name, with descriptions.
The function current_setting produces
equivalent output; see Section 10.26.1.
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 lightdb server version:
SHOW lightdb_server_version; lightdb_server_version ------------------------ 13.8-24.2 (1 row)
Show lightdb server version number:
SHOW lightdb_server_version_num; lightdb_server_version_num ---------------------------- 220400 (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)
Show all settings beginning with the parameter WAL%:
SHOW WAL%;
name | setting | description
-------------------------------+-----------+------------------------------------------------------------------------------------------------------------
wal_block_size | 8192 | Shows the block size in the write ahead log.
.
.
.
wal_writer_flush_after | 1MB | Amount of WAL written out by WAL writer that triggers a flush.
(19 rows)
Show all settings ending with the parameter %LEVEL:
SHOW %LEVEL;
name | setting | description
----------------------------------+---------+-----------------------------------------------------------
auto_explain.log_level | log | Log level for the plan.
.
.
.
wal_level | replica | Set the level of information written to the WAL.
(7 rows)
Show all settings including with the parameter %_FREEZE_:
SHOW %_FREEZE_%;
name | setting | description
-------------------------------------+-----------+-------------------------------------------------------------------------------
autovacuum_freeze_max_age | 200000000 | Age at which to autovacuum a table to prevent transaction ID wraparound.
.
.
.
vacuum_multixact_freeze_table_age | 150000000 | Multixact age at which VACUUM should scan whole table to freeze tuples.
(6 rows)
The SHOW command is a
LightDB extension.