Oracle SYSDATE, SYSTIMESTAMP, CURRENT_TIMESTAMP

SYSTIMESTAMP

• https://docs.oracle.com/cd/B19306_01/server.102/b14200/functions173.htm

• returns the system date, including fractional seconds and time zone, of the system on which the database resides.

• RAC 환경에서는 각 노드가 떠있는 서버의 시간이다.

  • https://dba.stackexchange.com/questions/121633/where-does-systimestamp-come-from-in-multi-server-oracle-rac-environment

    Up to 11g I know Oracle used the local OS time as the system time in a RAC environment, and I never heard that it changed so I'm comfortable saying it's still in place.
    You would sync all the servers together typically using NTP or another solution to ensure the time sync. Usually if your servers local time is out of sync even by 30 seconds or so, you will tend to see other issues such as Kerberos auth issues so it's unlikely they are far off from each other.

• SYSTIMESTAMP는 쿼리가 수행되는 시점의 시간.

CURRENT_TIMESTAMP

• return the current date and time in the session time zone.

SELECT SYSDATE, SYSTIMESTAMP, CURRENT_TIMESTAMP  FROM DUAL

SYSTIMESTAMP                    CURRENT_TIMESTAMP                     
------------------------------- --------------------------------------
22/07/06 05:47:52.181289000 GMT 22/07/06 14:47:52.181291000 ASIA/SEOUL