Expanding Capacity with Specific-Purpose Coservers

You can add one or more coservers to the database server and use the added coservers for the following purposes:

• To increase the permanent database capacity

  As your tables grow in size and your queries grow in complexity, you can easily increase data capacity and computing power by adding coservers to your existing database server configuration. Such increases in computing power and memory usually produce linear improvements in processing speed.

• To provide extra computing power for peak workload periods

  Your database server configuration might be adequate for daily processing, but inadequate when you run year-end or month-end reports at the same time you maintain daily processing.

  In such a situation, specific-purpose coservers can add parallel-processing power and temporary disk space. Consider creating one or more specific-purpose coservers configured with both the TEMPDATA and COMPUTE types. These coservers can be enabled during peak processing times to improve performance. During non-peak times, you can disable the coservers and use them for other purposes. Because specific-purpose coservers cannot host permanent tables, their database server-configured disk space is relatively small. Remaining disk space can be used for other applications that run at off-peak times.

• To make better use of a hot-standby node

  You can configure a compute coserver on the hot-standby node to utilize its resources while there are no failures in the system.

  If a failure occurs, you disable the compute coserver as part of the failover process to migrate the coserver from the failed node to the hot-standby node.

For information about how to add and manage coservers, see IBM Informix: Extended Parallel Server Administrator's Guide.