Online reorganization processing when the ALTER option is specified

When the ALTER option is specified, the INIT OLREORG command initiates a reorganization of an entire HALDB database to apply the database changes to all of the database partitions.

Upon receiving the INIT OLREORG OPTION(ALTER) command, an IMS system can alter a maximum of 10 partitions concurrently. If there are more than 10 partitions, those that are processed immediately are queued and altered as soon as processing completes for one of the partitions that were altered first.

While an IMS system reorganizes and alters a partition, the IMS system has ownership of the partition. The subsystem ID of the IMS system that owns a partition for alter processing is recorded in the OLRIMSID field of the partition record.

In a data-sharing environment, ownership of a partition is granted to the first IMS system that is available to alter the partition. If one IMS system is available to process ten partitions before any other IMS system becomes available, all ten partitions are processed by the single IMS system. If a partition is queued for alter processing, the partition will be processed by the first IMS system that can obtain ownership of the partition.

When alter processing starts, IMS updates the RECON records for every partition in the database with ALTER IN PROGRESS=YES, including for those partitions that are queued. While an IMS system is actively altering a partition, the partition record shows OLREORG CURSOR ACTIVE=YES.

After alter processing is complete for a partition, the partition record to shows PARTITION ALTERED=YES.