Hierarchy
SAP_BASIS (Software Component) SAP Basis Component⤷
BC-DB-DB2 (Application Component) DB2 for z/OS⤷
STU2 (Package) CCMS for DB2 for OS/390
Basic Data
| Data Element | DB2MOD_REC_AGE |
| Short Description | AGE parameter of MODIFY RECOVERY utility |
Data Type
| Category of Dictionary Type | Direct Type Entry | |
| Type of Object Referenced | No Information | |
| Domain / Name of Reference Type | ||
| Data Type | INT4 | 4-byte integer, integer number with sign |
| Length | 10 | |
| Decimal Places | 0 | |
| Output Length | 11 | |
| Value Table |
Further Characteristics
| Search Help: Name | ||
| Search Help: Parameters | ||
| Parameter ID | ||
| Default Component name | ||
| Change document | ||
| No Input History | ||
| Basic direction is set to LTR | ||
| No BIDI Filtering |
Field Label
| Length | Field Label | |
| Short | 3 | AGE |
| Medium | 19 | MODIFY RECOVERY AGE |
| Long | 40 | AGE parameter of MODIFY RECOVERY utility |
| Heading | 40 | AGE parameter of MODIFY RECOVERY utility |
Documentation
Definition
The MODIFY RECOVERY utility deletes records from the SYSIBM.SYSCOPY catalog table, related log records from the SYSIBM.SYSLGRNX directory table, and entries from the DBD. MODIFY RECOVERY should run regularly to clean up outdated information. This saves much space and, even more important, speeds up processes that access data from the tables mentioned above, for instance COPY utility and RECOVER utility.
MODIFY RECOVERY has a parameter AGE that can be maintained here. Valid values are from 0 to 32767. MODIFY RECOVERY deletes all records older than the specified number of days. If you specify 0, MODIFY RECOVERY is not used by SAP.
Recommended value
The recommended number depends on your environment and should be correlated to the "Number of GDG Generations" also configurable in transaction DB2J. This is due to the following reasons:
- MODIFY RECOVERY only cleans up records. The backup data sets themselves will not be deleted automatically. On the other hand, only in SYSIBM.SYSCOPY are the names of the backup data sets noted, so after having deleted these records, you won't be able to determine which backup data sets have to be deleted. There are two solutions to this problem: Either use GDGs or configure in SMS a retention period for Management Class of the data sets in question, that has the same value as the AGE parameter of MODIFY RECOVERY.
- A record in SYSIBM.SYSCOPY without the backup data set is useless.
- A backup data set without a record in SYSIBM.SYSCOPY can not be used by the RECOVER utility. You need to take a series of complicated steps to still use it (e.g. DSN1COPY or LOAD and very old archive logs). This should be reserved to emergency and won't be your normal mode of operation.
Having said that, now some recommendations:
- If you don't use GDGs or some other means to get rid of old backup data sets, don't use MODIFY RECOVERY from within SAP i.e. specify 0 for "AGE for MODIFY RECOVERY".
- The minimal number is the age of the last successful FULL IMAGE COPY.
- Correlate it to "Number of GDG Generations". Let's assume, that you specified a number for "Number of GDG Generations", which is sufficient to keep 6 months worth of backups. Correspondingly, you should specify 183 days for "AGE for MODIFY RECOVERY".
History
| Last changed by/on | SAP | 20130604 |
| SAP Release Created in | 700 |
