Recovery options for data sharing environments

Use the RECOVER utility to recover to currency or to a prior point in time.

Recovery to currency

This process is used to recover from damaged data by restoring from a backup and applying all logs to the current time. The recovery process operates similarly in the data sharing and non-data-sharing environments. Image copies are restored and subsequently updated based on changes recorded in the logs. In the data sharing group, multiple member logs are read concurrently in log record sequence.

Point-in-time recovery

This process discards potentially corrupt data by restoring a database to a prior point of consistency. Corrupt data might result from a logical error. The following point-in-time recovery options are available:

TORBA: This option is used to recover to a point on the log defined by a receive byte address (RBA). In a data sharing environment, TORBA can only be used to recover to a point prior to defining the data sharing group.
TOLOGPOINT: This option is used to recover to a point on the log defined by a log record sequence number (LRSN). The TOLOGPOINT keyword must be used when you recover to a point on the log after the data sharing group was defined. However, you can also use TOLOGPOINT in a non-data-sharing environment.
The LRSN is a 10-byte hexadecimal number derived from a store clock timestamp. LRSNs are reported by the DSN1LOGP stand-alone utility.
TOCOPY: This option is used to recover data or indexes to the values contained in an image copy without subsequent application of log changes.

Successful recovery clears recovery pending conditions and brings data to a point of consistency. In a data sharing environment, all pages associated with the recovered data entity are removed from the group buffer pool and written to disk.

Recovery using a system-level backup

The RECOVER utility can recover an object or a list of objects using a system-level backup, that is created with the BACKUP SYSTEM utility, as a recovery base.