1.SYSDATE
SYSDATE returns the current date and time set for the operating system on which the database server resides. The data type of the returned value is DATE, and the format returned depends on the value of the NLS_DATE_FORMAT initialization parameter. The function requires no
arguments. In distributed SQL statements, this function returns the date and time set for the operating system of your local database. You cannot use this function in the condition of a CHECK constraint.
In a multitenant setup existing PDBs and PDBs created later inherit the timezone of the system. If you want SYSDATE to return the timezone of the PDB, then you must set the initialization parameter TIME_AT_DBTIMEZONE to TRUE before starting the PDB.
You can change the timezone using ALTER SYSTEM SET TIME_ZONE or ALTER DATABASE db_name SET TIME_ZONE. You can set SYSTIMESTAMP to return system time by setting the initialization parameter TIME_AT_DBTIMEZONE to FALSE and restarting the database.
- SYSTIMESTAMP
SYSTIMESTAMP returns the system date, including fractional seconds and time zone, of the system on which the database resides. The return type is TIMESTAMP WITH TIME ZONE.
In a multitenant setup existing PDBs and PDBs created later inherit the timezone of the system.
If you want SYSTIMESTAMP to return the timezone of the PDB, then you must set the initialization parameter TIME_AT_DBTIMEZONE to TRUE before starting the PDB.
You can change the timezone using ALTER SYSTEM SET TIME_ZONE or ALTER DATABASE db_name SET TIME_ZONE.
You can set SYSTIMESTAMP to return system time by setting the initialization parameter TIME_AT_DBTIMEZONE to FALSE and restarting the database.
