I have two tables that have similar fields, one is the latest snapshot of data, while the other is a history. Since the one table is a subset and snapshot of the other (and contains hundreds of rows and opposed to the millions), when I insert into the History table, I have a trigger that does a pre-insert update on the Snapshot.

The Snapshot has
ID varchar[32] not null
A1 float
A2 float
DateTime_Stamp TIMESTAMP

What I discovered today was that the Update Trigger does not update if A1, A2 and DateTime_Stamp are all NULL. Can someone explain this; is it potentially a bug or is the lack of data (i.e. the NULL) something that cannot be updated?

Thanks.

Kurt.
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Never underestimate the Power of Denial.