HSSP image copies

If you use the image copy option of HSSP, IMS creates image copies of DEDB areas for you.

The image copy contains the after images of the HSSP PCB, and is a fuzzy copy. IMS logs all other PCB database changes as usual. During database recovery, you must apply any concurrent updates since the start of the image copy process. A fuzzy image copy can be created if a non-HSSP region updated the same DEDB area during the image copy process.

Definition: Fuzzy means that there might have been concurrent updates during the image copy process.

If, however, the image copy process does not complete successfully, this data set is simply returned to the set of available HSSP image copy data sets.

IMS uses the QSAM access method to create HSSP image copies. The primary allocation of image copy data sets must be larger than (or equal to) the DEDB area data set size.

IMS treats HSSP image copies like concurrent image copies, so you can use the Database Recovery utility (DFSURDB0) without telling it that the image copy is an HSSP image copy.

Restriction: You can only make an HSSP image copy if a database is registered with DBRC. Furthermore, you must initialize the image copy data sets using the INIT.IC command.