Hi,

I’ve come across something that is either a bug or is just my misunderstanding of how MonetDB deals with NULL results from boolean expressions.

The issue I’m having is the OR and AND expressions behave differently in when evaluating a bollean expression where one of the variable is NULL (This is using  version 11.15.19)

If I run a query:

SELECT ([some expression that evaluates to NULL] OR [some expression that evaluates to True] ) as “Result” – the returned value is <null>

If I try

SELECT ([some expression that evaluates to NULL] AND [some expression that evaluates to True] ) as “Result” – the returned value is True

This would seem to suggest the AND evaluation is ignoring NULL or Treating NULL as meaning True whereas OR is propagating it. Which is correct and is this a bug?

Thanks,

Scott Mathieson

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