Configuration flexibility

Data sharing lets you configure your system environment much more flexibly with operational systems, decision support systems, and shared data management.

As the following figure shows, you can have more than one data sharing group on the same Parallel Sysplex®. You might, for example, want one group for testing and another group for production data. This example also shows a single, non-data sharing Db2 subsystem.

Figure 1. A possible configuration of data sharing groups. Although this example shows one Db2 subsystem per z/OS®, a z/OS image can support multiple Db2 subsystems.
Begin figure description. This Parallel Sysplex supports two data sharing groups and a single DB2 subsystem. One group has three members, and the other has two members. End figure description.

Flexible operational systems

The following figure shows how, with data sharing, you can have query user groups and online transaction user groups on separate z/OS images. This configuration lets you tailor each system specifically for that user set, control storage contention, and provide predictable levels of service for that set of users. Previously, you might have had to manage separate copies of data to meet the needs of different user groups.

Figure 2. Flexible configurations with data sharing. Data sharing lets each set of users access the same data, which means that you no longer need to manage copies.
Begin figure description. Without data sharing, each user group on different z/OS images has its own data copy. With data sharing, multiple user groups can share the same copy. End figure description.

Flexible decision support systems

The following figure shows two different decision support configurations. A typical configuration separates the operational data from the decision support data. Use this configuration when the operational system has environmental requirements that are different from those of the decision support system. For example, the decision support system might be in a different geographical area, or security requirements might be different for the two systems.

Db2 offers another option—a combination configuration. A combination configuration groups your operational and decision support systems into a single data sharing group and offers the following advantages:
  • You can occasionally join decision support data and operational data using SQL.
  • You can reconfigure the system dynamically to handle fluctuating workloads. (You can dedicate CPCs to decision support processing or operational processing at different times of the day or year.)
  • You can reduce the cost of computing:
    • The infrastructure used for data management is already in place.
    • You can create a prototype of a decision support system in your existing system, and then add processing capacity as the system grows.
Figure 3. Flexible configurations for decision support. Data sharing lets you configure your systems in the way that works best in your environment.
Begin figure summary. A typical configuration is shown side-by-side with a combination configuration. Detailed description available.

If you want a combination system configuration, you must separate decision support data from operational data as much as possible. Buffer pools, disks, and control units that you use to decide on a support system should be separate from those that you use in your operational system. This separation greatly minimizes any negative performance impact on the operational system.

If you are unable to maintain the needed level of separation, or if you have separated your operational data for other reasons, such as security, using a separate decision support system is your best option.

Flexible shared data management

Db2 data sharing can simplify the management of applications that must share data, such as a common customer table. Perhaps these applications were split in the past for capacity or availability reasons. But with the split architecture, the shared data must be synchronized across multiple systems (that is, by replicating data).

Db2 data sharing gives you the flexibility to configure these applications to access a single data sharing group. It also allows you to maintain a single copy of the shared data that can be read and updated by multiple systems with good performance. This is an especially powerful option when data centers are consolidated.