Partially Documented Parameters

Abstract

Figuratively speaking, the Oracle database management system has a tremendous number of knobs to turn and switches to flip. Oracle9i Release 2 has 257 documented parameters, Oracle10g Release 2 has 258, and Oracle11g Release 1 has 294. Presumably there is no single DBA who has memorized the meanings and permissible values for all those parameters. The Oracle Database Reference manual of each respective release is the definitive source for documented initialization parameters. This chapter scrutinizes the partially documented parameters AUDIT_SYSLOG_LEVEL, PGA_AGGREGATE_TARGET, EVENT, and OS_AUTHENT_PREFIX and provides information that is absent from the Oracle Database Reference manual. Both AUDIT_SYSLOG_LEVEL and OS_AUTHENT_PREFIX are related to database security. EVENT is a curious parameter in the sense that the parameter itself is documented, but permissible values are not. Among other things it may be used to collect more evidence when errors occur or gather diagnostic information under the supervision of Oracle Support Services. From a performance perspective, learning how PGA_AGGREGATE_TARGET is handled internally allows a DBA to significantly reduce the response time of large sort operations.