Impact on Indexes When Mixing VARCHAR and NVARCHAR Types

You may have heard, or read, that you should not mix VARCHAR and NVARCHAR datatypes, especially when one of them is a JOIN or WHERE predicate / condition, as doing so will invalidate indexes. While it is always best to have all datatypes be the same for a particular operation (comparison, concatenation, etc), the actual… Continue reading Impact on Indexes When Mixing VARCHAR and NVARCHAR Types