The System i5 Change Selector capture does not access the user source table, but during initialization a brief share lock is required. The System i5 Change Selector normally obtains all the information about a user table for which it is capturing data from the DB2 SQL catalog. This is all done at program initialization. However, during initialization there is a brief call to the system for each table where a share lock is required to obtain required metadata information about the table. This information is obtained by the following SQL calls: PREPARE and DESCRIBE.
If this information cannot be obtained, because some other process has an exclusive lock on the table, then the Change Selector aborts.
To start the Change Selector on the IBM i from the command line (for example, so that you can see the job log to debug), use one of the following commands:
CALL PGM (see Use the CALL PGM command)
SBMJOB (see Use the SBMJOB command)