Record deactivation

If an error occurs while an application program is updating a DEDB, it is not necessary to stop the database or even the area. IMS continues to allow application programs to access that area.

IMS only prevents the application programs from accessing the control interval in error by creating an EQE for the error CI. If there are multiple copies of the area, chances are that one copy of the data will always be available. It is unlikely that the same control interval will be in error in all copies of the area. IMS automatically makes an area data set unavailable when a count of 11 errors has been reached for that data set.

Record deactivation minimizes the effect of database failure and errors to the data in these ways:

• If multiple copies of an area data set are used, and an error occurs while an application program is trying to update that area, the error does not need to be corrected immediately. Other application programs can continue to access the data in that area through other available copies of that area.
• If a copy of an area has a number of I/O errors, you can create a new copy from existing copies of the area using the DEDB Area Data Set Create utility. The copy with the errors can then be destroyed.