DECODE question

Given the following two columns:

ACCTD_AMOUNT_DUE_REMAINING      NOT NULL NUMBER
AMOUNT_DUE_REMAINING            NOT NULL NUMBER

What does the following statement mean?

sum(decode(NULL,'Y',acctd_amount_due_remaining,amount_due_remaining))

What is the interpretation of the "DECODE(NULL,'Y',..."?

Thanks in advance. Received on Mon Nov 11 2002 - 20:02:31 CST