Constant and Macro

Table 1 lists the constants and macros that can be used in openGauss.

Table 1 Constant and macro

Parameter	Description	Example
CURRENT_CATALOG	Specifies the current database.	postgres=# SELECT CURRENT_CATALOG; current_database \------------------ postgres (1 row)
CURRENT_ROLE	Specifies the current user.	postgres=# SELECT CURRENT_ROLE; current_user \-------------- omm (1 row)
CURRENT_SCHEMA	Specifies the current database mode.	postgres=# SELECT CURRENT_SCHEMA; current_schema \---------------- public (1 row)
CURRENT_USER	Specifies the current user.	postgres=# SELECT CURRENT_USER; current_user \-------------- omm (1 row)
LOCALTIMESTAMP	Specifies the current session time (without time zone).	postgres=# SELECT LOCALTIMESTAMP; timestamp \---------------------------- 2015-10-10 15:37:30.968538 (1 row)
NULL	This parameter is left blank.	N/A
SESSION_USER	Specifies the current system user.	postgres=# SELECT SESSION_USER; session_user \-------------- omm (1 row)
SYSDATE	Specifies the current system date.	postgres=# SELECT SYSDATE; sysdate \--------------------- 2015-10-10 15:48:53 (1 row)
USER	Specifies the current user, also called CURRENT_USER.	postgres=# SELECT USER; current_user \-------------- omm (1 row)