Background processes are database processes running in the background. The processes enhance database performance and maintain data integrity in the event of a system crash or media failure.
There are four background processes:
Before-image Writer (BIW): Writes full BI buffers to the BI files on disk.
After-image Writer (AIW): Writes full AI buffers to the AI files on disk.
Asynchronous Page Writer (APW): Writes modified database blocks to disk.
Watchdog (PROWDOG): Cleans up after improperly terminated self-service clients as well as the remote clients of lost servers.
Before-image Writer (BIW): Writes full BI buffers to the BI files on disk.