The SECOND function returns the seconds part of a value. The argument must be a time, timestamp, or a valid character string representation of a time or timestamp that is neither a CLOB nor a LONG VARCHAR. The result of the function is a large integer. If the argument can be null, the result can be null; if the argument is null, the result is the null value.
SECOND ( expression )
Assume that the column RECEIVED (timestamp) has an internal value equivalent to 1988-12-25-17.12.30.000000.
SECOND(RECEIVED)
Returns the value 30.