Only one suspension window can be open for a capture registration at a time.

If you issue a SUSPEND_REGISTRATION command followed by an ACTIVATE_REGISTRATION command and then issue another SUSPEND_REGISTRATION command before the ECCR starts processing the change records later than the first suspension window, unpredictable results might occur. Wait until the ECCR has processed all of the change records with timestamps earlier than the activation timestamp before issuing another suspension request.

To generate suspension and activation timestamps, the utility uses the current system time at the time when the SUSPEND_REGISTRATION or ACTIVATE_REGISTRATION command is processed, without any adjustment for the local time. These timestamps are included in messages and in the

Suspend Time

and

Active Time

fields of the PowerExchange Navigator Resource Inspector. These timestamps define the start and end of the

suspension window

. The utility uses current system time for the timestamps because the supported database types store timestamps in CDC records in current system time.

You must issue an ECCR REFRESH command after issuing any PWXUCREG command that changes the registration status. This refresh process enables the ECCR to read the registration information from the CCT data set again to get the suspension and activation timestamps and the new registration status.

The first time you activate a capture registration in the PowerExchange Navigator, the activation timestamp is not set. The

Active Time

field is blank until you use the PWXUCREG utility to submit a SUSPEND_REGISTRATION command followed by an ACTIVATE_REGISTRATION command.

If the ECCR ends abnormally and then warm starts within the same suspension window, the utility issues a message when it encounters the first change record in the suspension window to be discarded.

If you have multiple registrations with the same registration tag name, you must suspend or reactivate each one. The utility cannot process all registrations with the same tag name in a single SUSPEND_REGISTRATION or ACTIVATE_REGISTRATION command.

When discarding change records for a suspended registrations, the ECCR verifies that the associated UOW started within the suspension window. If the UOW started before the beginning of the suspension window, the ECCR either issues a warning and continues or issues an error message and ends, depending on the ON_SUSPENSION_ERROR_CONTINUE parameter setting in the ECCR configuration file.

When capturing change records for an activated registration, the ECCR verifies that the associated UOW started after the suspension window closed. If the UOW started before the end of the suspension window, the ECCR either issues a warning and continues or issues an error message and ends, depending on the ON_SUSPENSION_ERROR_CONTINUE parameter setting in the ECCR configuration file.

To have the ECCR discard change records that have timestamps earlier than the current system time, use the DROP_OLD_REGISTRATION_DATA command. You can issue this command for an Active registration only. This command sets a special suspension window that extends from the earliest point in the logs to the current system time.

You can cancel a suspension or activation operation before you refresh the ECCR for the registration status change. You might want to cancel a suspension or reactivation request because it was issued at the wrong time related to the database processing or the command input contained errors. The cancel command resets the suspension or activation timestamp.

In the PowerExchange Navigator, you can change the registration

Status

value of

Suspended

only to

History

. Make this change only if you no longer want to use the registration for change capture. You cannot change a registration

Status

value of

Active

to

Suspended

from the PowerExchange Navigator. You must use the PWXUCREG utility to make this status change.