How a HALDB Online Reorganization impacts IMS logging

The online reorganization of a HALDB partition generates X'50' database change log records for all of the data in the partition.

IMS also logs other HALDB Online Reorganization information in a small number of X'29' log records. Thus, the total amount of log data generated by a HALDB Online Reorganization is considerably greater than the amount of data in the partition.

Reorganizing partitions online, especially reorganizing multiple partitions in parallel on the same IMS system, can generate sufficient log data to impact normal transaction processing. The large number of log records that are generated can also affect the rate of OLDS switches and log archiving.