Phase 2 - write record to system log

Database and message records are written to the IMS system log. After logging, MSDB records are updated, the DEDB updates begin, and messages are sent to the terminals.

DEDB updates are applied with a type of asynchronous processing called an output thread. Until the DEDB changes are made, any program that tries to access unwritten segments is put in a wait state.

If, during application processing, a Fast Path program issues a call to a database other than MSDB or DEDB, or to an alternate PCB, the processing is serialized with full function events. This can affect the performance of the Fast Path program. In the case of a BMP or MPP making a call to a Fast Path database, the Fast Path resources are held, and the throughput for Fast Path programs needing these resources can be affected.