Type 1

When using XAE Type 1 databases, the entire database is seen by the user, but the database is actually composed of the different groups of variables in the different computers.

Each computer updates its own variables in memory in E/CSA memory. But all other computers can see these values because a checkpointed copy of the same variables exists in the Coupling Facility.

For example, assume that each computer has its own JES2 status variable that it can update. However, the operator can see all these JES2 status variables in the Sysplex from a single screen, and CMEM rules, or Control‑O rules, for example, can resolve these values from computers other than the one in which the rule is triggered. This kind of database is useful when the application does not really share data across computers, but a single point of management for the entire Sysplex is required.

Type 2

When using XAE Type 2 databases, all components in a Sysplex, that is, computers, rules, jobs, and so on, share the same image of the database. If one computer updates the object, all other computers share the update.

For example, if computer A increments an event count by one, and then computer B increments the same event count by one, the shared counter is incremented by two, and is seen and accessible by both computers.