Key Definition Area

All unused or reserved areas must be initialized to binary zeros.

Offset Type Description of the Field
0 pic xx comp-x Component count. For ordinary keys, the component count is 1. For split keys, the component count is the number of components making up the split key.
2 pic xx comp-x Offset to first component definition area for this key. This offset is relative to the start of the global information area, starting at 0.
4 pic x comp-x Key flags:
  • Bit 7 - Reserved
  • Bit 6 - Duplicates allowed
  • Bit 5 - Reserved
  • Bit 4 - Set to indicate that this is the prime key. If this is not set for any key, the File Handler assumes that the first key is the prime key.
  • Bit 3 - Reserved
  • Bit 2 - Reserved
  • Bit 1 - Sparse key. See offset 6.
  • Bit 0 - Reserved
5 pic x comp-x Compression flags:
  • Bits 7 - 4 Reserved
  • Bit 3 - Compression of trailing nulls
  • Bit 2 - Compression of trailing spaces
  • Bit 1 - Compression of leading characters
  • Bit 0 - Compression of duplicates
6 pic x comp-x Sparse character. If bit 1 of the key flags (offset 4) is set, the key is suppressed if it is entirely made up of this character.
7 pic x(9) comp-x Reserved
Parent topic: Data Structures