> So my question is: is storing only 'T' and leaving nulls any > less expensive than storing both 'T' and 'F' in a lookup table?
I believe the CHAR(1) NOT NULL columns will be simpler and slightly more efficient for the database to handle. NULL processing is complex and adds both space and time overheads; for a column which is boolean true/false my preference would be the CHAR(1) NOT NULL implementation. thanks, bryan
