This section deals with the estimation of the right time for rollover and rollback.

We recommend performing the rollover to the bridge subsystem outside the peak hours. Some steps after the rollover, such as the smart switch in the EU_SWITCH_ZDM phase, need an exclusive database lock on the table to switch the table spontaneously.

Analyze the system load (dialog and batch load) and the alignment of the rollover to the bridge subsystem best in close collaboration with the functional teams. As of this point in time, read-only restrictions are active for the read-only tables.

Also calculate the rollover to the bridge subsystem based on the runtimes from the last pre-production text cycle performed with an up-to-date copy of the production.

Assuming, as per the upgrade analysis file (upgana.xml), the net-runtime of the bridge subsystem in the dress rehearsal cycle took approximately hours. Add then a buffer to calculate the recommended runtime of the bridge subsystem in production.

If the net runtime of the bridge subsystem in the last test cycle took some hours according to the upgrade analysis file (upgana.xml), add to the calculated runtime of the bridge subsystem in production a buffer.