Table 10-1 shows the operation modes of the rebalancing utility.
Table 10-1 Operation modes of the rebalancing utility
Operation mode | Description |
---|---|
Shared mode | Accesses to the table are permitted during execution of pdrbal. Use this mode for a system that cannot stop online applications due to 24-hour operation. |
Exclusive mode | Accesses to the table are not permitted during execution of pdrbal. Use this mode for a system that can deny access to the table and execute batch processing at night. |
In the shared mode, a table being rebalanced is accessible. To execute the utility in the shared mode, specify share in the -k option.
The shared mode requires acquisition of log information as well as repeated allocation and release of the resources that are required by concurrently executing SQL. Therefore, the time required for a rebalance operation in the shared mode is longer than in the exclusive mode.
Figure 10-3 Example of rebalancing utility execution in shared mode
In the exclusive mode, no access is allowed to a table being processed by the rebalancing utility. To execute the rebalancing utility in the exclusive mode, specify exclusive in the -k option.
In the exclusive mode, acquisition of log information is optional. The required resources are allocated and released only once, and batch index creation is permitted; therefore, the time required for the rebalancing operation is less than in the shared mode.
Figure 10-4 Example of rebalancing utility execution in exclusive mode