Getting the Current Date and Time
CURRENT_TIMESTAMP functional operators return date and time values based upon the moment of execution of a SQL statement using the server’s clock and time zone. For a single SQL statement, the same value is used for each evaluation of
CURRENT_TIMESTAMP within that statement. This means that if multiple rows are updated, as in the following statement, each data row will have the same value in the aTime column:
UPDATE aTable SET aTime = CURRENT_TIME;
Similarly, if row buffering occurs in a fetch via the remote protocol, then the value of
CURRENT_TIME is based on the time of the
OPEN of the cursor from the database engine, and not on the time of delivery to the client.
You can specify
CURRENT_TIMESTAMP as the default clause for a domain or column definition.