Define physical and logical files using DDS

This topic provides information about coding physical and logical files that use DDS, and describes the positional entries used by these files.

• Define a physical file using DDS
  You use file-level, record-level, field-level, and key-field-level entries to define a physical file with DDS.
• Define a logical file using DDS
  A logical file determines how data records are selected and defined when read by an application program. A logical file can be a simple, multiple format, or join logical file.
• Positional entries for physical and logical files (positions 1 through 44)
  The first 44 positions of the DDS form are called positional entries.