Hi

> Precisely. Don't write check constraints with logic that doesn't provide

the check you require. In simple terms: garbage in, garbage out.

This is as the 50-day bug in Windows 98.
You could insist, that it is not a bug, but a feature to force restarts of
windows every 50 days.
I still regard this as a bug.

> I could go on to say NEVER define a check constraint based an aggregation.

Think about it a little....

Check constraints need to keep the database consistent, where consistent
means that the condition is fullfilled.
I know that inserted data is only visible to the inserting
connection/transaction. However, commits are atomic serializable action that
could enforce check-constraints in the right way. Even with aggregation
functions.

Regards,
Steffen


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