The ADAULD utility unloads an Adabas file. Adabas files are unloaded to:
permit the data to be processed by a non-Adabas program. In this case, the file must also be decompressed after unloading using the DECOMPRESS function of the ADACMP utility.
create one or more test files, all of which contain the same data. This procedure requires that a file be unloaded, and then reloaded as a test file having a different file number.
change the field definition table (FDT). This requires that the file be unloaded, decompressed, compressed using the modified field definitions, and reloaded. If the ADADBS utility is used to add field definitions to a file, the file does not need to be unloaded first.
The sequence in which the records are unloaded may be
| physical | the order in which they are physically positioned within Data Storage. |
| logical | a sequence controlled by the values of a user-specified descriptor. |
| ISN | ascending ISN sequence. |
Selection criteria (SELCRIT/SELVAL) are optionally used to indicate a subset of records to be unloaded:
If no such criterion is provided, all records are unloaded in physical sequence.
If a selection criterion is specified but no sort sequence (SORTSEQ), the specified records are unloaded in ISN sequence.
If both a selection criterion and a sort sequence are provided, the selected records are sorted in the Work pool area of the nucleus and are unloaded in the specified sort sequence.
If no records that match the selection criteria are found, ADAULD creates a file containing only the FDT and issues condition code 4 in register 15.
The unloaded record output is in compressed format. The output records have the same format as the records produced by the ADACMP utility.
When using the MODE=SHORT option, descriptor entries (which are required to create the normal index and upper index for the file) are omitted during the unload process. This reduces the time required for unloading. Note, however, that output created using MODE=SHORT has a different FDT from the same file unloaded without MODE=SHORT, since all descriptor information is removed.
Notes: