Operating with data sharing

Most data sharing operations are accomplished by using commands to DB2® for z/OS®.

Commands for data sharing environments
As you begin to operate your data sharing environment, you should understand how commands work in a data sharing environment.
Effect of data sharing on sequence number caching
DB2 always assigns sequence numbers in order of request.
Starting a data sharing member
To start members of a DB2 data sharing group, you must enter a START DB2 command for each member of the group.
Stopping a data sharing member
Stop individual members of a DB2 data sharing group by using the STOP DB2 command.
States of connections and structures after stopping DB2
When DB2 allocates its coupling facility structures, it specifies a disposition for the structures and for connections to the structures after a normal or abnormal termination.
Submitting work to be processed
The methods that you use to submit work in a non-data sharing environment do not need to change for data sharing. However, you might find it to your advantage to use group attachment names and subgroup attachment names to direct jobs.
Monitoring the group
Monitoring data sharing groups includes tasks such as monitoring the database, and monitoring information about the group, structures, and group buffer pools.
Controlling connections to remote systems in a data sharing environment
Controlling DDF connections in a data sharing environment is somewhat different from controlling DDF connections in a non-data sharing environment.
Logging environment for data sharing
In a data sharing environment, the member subsystems still maintain separate recovery logs. Each manages its own active and archive log data sets and records those in its own bootstrap data set (BSDS).
Recovering data
The procedures for data recovery are fundamentally the same for data sharing as for non-data-sharing environments. Data sharing involves one catalog, but many logs and BSDSs. In addition to disk and cache controllers, the coupling facility adds a possible point of failure and requires appropriate procedures for data recovery.
Restarting DB2 after termination in a data sharing environment
After a failure or after a normal shutdown of DB2, you can restart DB2 with the -START DB2 command.
Starting duplexing for a structure
When duplexing starts, a period exists in which activity to the structure is quiesced. For this reason, you should start duplexing during a period of low activity in the system.
Stopping duplexing for a structure
If you need to stop duplexing, you must first decide which instance of the structure is to remain as the surviving simplexed structure.
Shutting down the coupling facility
Create a plan for those cases in which it is necessary to shut down a coupling facility to apply maintenance or perform another type of reconfiguration.

Parent topic: Introduction to DB2 data sharing