The Adabas Delta Save Facility (DSF) offers significant enhancements to ADASAV utility processing by backing up and restoring only the changed (delta) portions of Adabas databases.
Note:
If the Adabas Delta Save Facility is not
installed on your system, the icon will not be displayed in your
Adabas Manager tree-view.
To view the Delta Save information:
Select an Adabas database in tree-view and expand it.
Select Delta Save Facility in tree-view.
In detail-view, a table displays the Delta Save Facility status as well as the following allocation information:
Number of Full Saves
Last Full Save Date
Number of Delta Saves
Last Delta Save
DLOG Area Size, which is the number of Associator blocks to be allocated. The area must be large enough to hold all blocks changed between two consecutive Delta Save operations. About 5 bytes of DLOG area storage are needed for every database write operation. To calculate the size of the DLOG area, see Calculating the DLOG Area Size in the Delta Save Facility section of the Adabas for Mainframes documentation.
DLOG Area Usage (%)
DLOG Area Location (Start RABN), which is the first RABN to be allocated.
Device Type, the device type to be used for DLOG area allocation.
To disable the Delta Save Facility, click on .
Note:
When DSF logging is disabled, you may no longer perform Delta Save
operations. To enable DSF logging again, you will need to do a full database
save using ADASAV SAVE. For that reason you will be prompted to confirm that
you want to disable DSF logging.
To display files modified by utilities:
Select Delta Save Facility in the tree-view and right-click on it.
Select on the drop-down menu.
In detail-view, the Delta Save Facility - Files Modified table displays the files modified by utilities, indicating the name and number of the files changed as well as the following information:
total blocks changed in all logged areas
total AC/DS blocks used, changed, and the percentage of the used that were changed
total index blocks used, changed, and the percentage of the used that were changed
Separate totals for the number of DS/AC blocks and index blocks changed for all files listed are displayed in a second table.
To display the size estimate for delta:
Select Delta Save Facility in the tree-view and right-click on it.
Select on the drop-down menu.
In detail-view, the Delta Save Facility - Estimated Number of Changed Blocks table displays an estimate of the number of database blocks that would be saved in a Delta Save operation at the current time.
Note:
The estimate is not precise: the actual size may be larger or
smaller.
The fixed area includes the blocks for the first 30 RABNs, all FDTs and all FCBs. Separate totals are provided for the number of index blocks as opposed to the number Data Storage and address converter blocks changed by utilities. The calculated number of blocks for the DLOG area is a rounded number. The total of all blocks to be saved is approximate to the nearest 100.
