Comparison Compatibility Rules

The following table defines the compatibility of data types for comparisons. In some cases, columns can be mapped, but cannot be used as Match Key columns. For example, if you compare source data type Char to source data type Numeric, the data types are compatible, but the pairing cannot be specified as a Match Key.

Source Data Type Char (1) Numeric Boolean Date/Time (2) Interval
Char (1) Yes (9) Yes (4) Yes (4, 8) No No
Numeric Yes (4) Yes Yes (4, 7) No No
Boolean Yes (4, 8) Yes (4, 7) Yes No No
Date/Time (2) No No No Yes (3, 5) No
Interval No No No No Yes (6)
Note:
  1. Includes Char, VarChar, NChar, NVarChar, Binary, VarBinary. You cannot compare multi-byte or Unicode character data to binary or single-byte character data.
  2. Includes Date, Time, DateTime, Timestamp, Timestamp with Time Zone, Timestamp with Local Time Zone.
  3. It is recommended that you compare Oracle Timestamp with Time Zone columns to Timestamp with Time Zone columns only, and Timestamp with Local Time Zone columns to Timestamp with Local Time Zone columns only. Comparison to columns of different data types may produce unexpected results due to Oracle assumptions for storing and retrieving this data.
  4. Pairing cannot be specified as a Match Key column.
  5. Comparison is valid as long as both columns have the same high-order component. For example, a DB2® Timestamp may be compared with an Informix® DateTime column only when the Informix column includes a ‘year' component.
  6. YearMonth interval columns can be compared to YearMonth interval columns only. DayTime or DaySecond interval columns can be compared to DayTime or DaySecond interval columns only.
  7. In Numeric/Boolean comparisons, when Numeric value is 0, then Boolean value is False. When Numeric value is anything other than 0, then Boolean value is True.
  8. In Char/Boolean comparisons, when Char value starts with ‘T', ‘t', ‘Y', 'y', or ‘1', Boolean value is True. When Char value starts with ‘F', ‘f', ‘N', 'n', ‘0', Boolean value is False.
  9. Comparisons of binary with multi-byte or Unicode data are not valid.