DB_WRITERS (Oracle)

This parameter determines the number of Oracle database writer processes that are started at database instance startup. Each database writer consumes one semaphore and an amount of process memory. Database writers are used by Oracle to write out modified blocks from the SGA to disk.

SAP systems generally use one database writer process. It is advisable to increase this amount if you will be performing comprehensive update or insert activities. For medium to large configurations, set this parameter so that there is one database writer process per Oracle data file disk. As there are several factors which determine the usefulness of changing this parameter, it is recommended to check with an Oracle or SAP specialist before modifying its value.