Additional considerations for describing database files that contain DBCS data

Be aware of these considerations when describing a database file that contains double-byte character set (DBCS) fields.

  • If you describe DBCS fields in the DDS, the system treats the file as a DBCS file. You do not need to specify IGCDTA(*YES) on the file creation command to identify the file as DBCS.
  • The data type of a field in a physical file can be changed as follows when you refer to that field in a logical file:
    Physical file data type Logical file data type
    J J, O, E, H, G
    O O, H
    E O, E, H
    A A, O, E, H
    H J, O, E, A, H
    G G, O, J, E
    Note: When the physical file data type is character (A) or hexadecimal (H), and the logical file data type is DBCS-only (J) or DBCS-either (E), the physical file field length (columns 30 through 34) must be an even number greater than or equal to 4.
  • DDS treats DBCS key fields as character fields (the data type specified in position 35 is O).
  • DDS uses the EBCDIC collating sequence to sort DBCS data.
  • Any key field sequencing keywords that can be used with character fields can be used with DBCS fields, except the following keywords:
    ALTSEQ
    DIGIT
    ZONE
  • Use bracketed-DBCS data anywhere comments and character strings are allowed.
  • Any bracketed-DBCS field except a field with data type J can be compared with a character field (data type A).
  • A DBCS-graphic field can be compared only with another graphic field.
  • The following validity checking keywords can be specified on DBCS fields:
    COMP
    RANGE
    VALUES
  • When specifying the VARLEN keyword in a physical file, the minimum allowed length for the allocated length is 4 for a bracketed-DBCS field. The minimum allowed length for the allocated length is 1 for a DBCS-graphic field.