Which three are amongst the categories into which column definitions are classifies by the Database Migration Assistant for Unicode (DMU)?

The DMU identifies alphanumeric columns whose stored byte sequences will be invalid in the chosen Unicode character set after conversion, classifying them as requiring remediation before migration.

Alphanumeric columns needing conversion to a different binary representation are not a standalone DMU classification category - the DMU's primary categories focus on validity issues, size breaches, and columns already compatible.

The DMU scans date columns and flags those whose binary representation will be invalid after conversion to the target Unicode character set, as these can be affected by the encoding context of the database.

Numeric columns are also analyzed by the DMU and classified when their binary representation will be invalid after converting to the chosen Unicode character set, ensuring all column types are assessed.

Numeric column data does not expand in size during Unicode character set migration because numeric types use fixed-width binary storage, so this is not a valid DMU classification category.

Alphanumeric columns requiring no conversion are not listed as one of the distinct DMU column classification categories that the tool uses to report migration issues.