bdfd1m25Database Administration

Files Containing Fixed-Position References

Figure 76 shows the DBDEF statements required to define this type of file structure. This example includes the FVN parameter because the overflow blocks are in a different format from the prime blocks.

Figure 76. File Containing Only Fixed-Position References (CBV=3)


Notes:

  1. The overflow blocks have a different format (no embedded addresses). If the PFC parameter is used, the overflow block would be identical to the prime block. The PFC parameter is set to -1 (no forward chain pointer), but ADR=zzzzFCH-zzzzBID defines the position of the pointer.

  2. A separate definition is used for the overflow blocks. The FVN parameter is used to identify the definition. The FNR parameter is used in the ID3 statement to refer to that definition.

  3. This example shows a file ('HF') which contains 2 references, at fixed locations in the file (zzzzFA1 and zzzzFA2).

  4. Both references point to more 'HF' files.

  5. The 'HF' overflow records use standard forward chaining, but contain no embedded references.