DDM-related DDS keywords and information

The information about DDS keywords that relates specifically to DDM is provided in this topic.

Considerations for creating local files:
- The following DDS keywords cannot specify the name of a DDM file: REFACCPTH, and FORMAT.
- The DDS keywords REF and REFFLD can specify the names of DDM files to refer to remote files; however, the remote files must be on an iSeries™ server or a System/38™. When a DDM file name is specified as the database file name in either keyword, it refers to the DDM file on the source server, and the referred to field name and record format name refer to a field and record format used in the remote file on the target server.
Considerations for creating logical files when the remote server is not an iSeries server:
- At least one key field must be specified in the record format for the logical file.
- Only one file can be specified on the PFILE keyword.
- SELECT and OMIT functions are not supported.
- Logical join files are not supported.
- Field names of remote physical files have the naming convention of F00001, F00002, F00003, and so forth (Fnnnnn) for nonkeyed fields and K00001, K00002, K00003, and so forth (Knnnnn) for keyed fields.
  The exception to this naming convention is when the target server is a System/38 and the physical file was created locally. In this case, the field names are the same as the field names specified when the physical file was created.
- All the fields defined for the logical file must be specified in the same order as defined in the physical file. This can be done by default.
- The SST keyword can be used to access partial fields of the physical file. The use of two or more substring fields is required to define the entire physical field. In addition, the partial fields must be in the same order as defined in the substring field of the physical file.
- The CONCAT keyword can be used to group physical file fields into one logical field. The concatenation order of the fields must be in the same order as defined in the physical file.
- The fields of the physical file must be specified in the same order as defined in the physical file.
Considerations for using the VARLEN DDS keyword when creating files on a non-iSeries target server:
- Target server must support variable-length record files.
- Only one variable-length field is allowed in the file format and it must be the last field.
- The field with the VARLEN keyword must not be a key field.
PFILE and JFILE considerations for creating remote files:
- The record format name specified for the physical file in the DDM file on the JFILE or PFILE keyword must be the same name as the DDM file that represents the remote physical file.
- When creating a logical file, the file specified on PFILE or JFILE must be a DDM file, and the location for each physical file in the DDM file on the JFILE or PFILE keyword must be the same as the location of the DDM file for the logical file. In other words, the physical files and logical file must be on the same remote server.
If the remote server is a release 1.0 or 1.2 iSeries server, attempting to create a file using the FCFO keyword will fail.

When the server is not an iSeries server, these keywords are either ignored or not supported for logical files:

ABSVAL
ACCPTH
ALIAS
ALL
ALTSEQ
CHECK
CMP
COLHDG
COMP
DIGIT
DYNSLT

EDTCDE
EDTWRD
FCFO
FLTPCN
FORMAT
JDFTVAL
JDUPSEQ
JFILE
JFLD
JOIN
JREF

LIFO
NOALTSEQ
RANGE
REFSHIFT
RENAME
SIGNED
TEXT
TRNTBL
VALUES
ZONE

When the server is not an iSeries server, these keywords are either ignored or not supported for physical files:

ABSVAL
ALTSEQ
CHECK
CMP
COLHDG
COMP
DIGIT

EDTCDE
EDTWRD
FCFO
FLTPCN
FORMAT
LIFO
NOALTSEQ

RANGE
REFSHIFT
SIGNED
TEXT
VALUES
ZONE