Which two statements are true regarding the Automatic Diagnostic Repository (ADR) in
Oracle Database 11g? (Choose two.)
A.
A single ADR can support multiple ADR homes for different database instances.
B.
The alert files are stored in XML file format in the TRACE directory of each ADR home.
C.
If the environmental variable ORACLE_BASE is set, then DIAGNOSTIC_DEST is set to
$ORACLE_BASE.
D.
The BACKGROUND_DUMP_DEST initialization parameter overrides the
DIAGNOSTIC_DEST initialization parameter for the location of the alert log file.
Explanation:
The ADR root directory is known as ADR base. Its location is set by the
DIAGNOSTIC_DEST initialization parameter. If this parameter is omitted or left null, the
database sets DIAGNOSTIC_DEST upon startup as follows:
If environment variable ORACLE_BASE is set, DIAGNOSTIC_DEST is set to the directory
designated by ORACLE_BASE.
If environment variable ORACLE_BASE is not set, DIAGNOSTIC_DEST is set to
ORACLE_HOME/log
Within ADR base, there can be multiple ADR homes, where each ADR home is the root
directory for all diagnostic data—traces, dumps, the alert log, and so on—for a particular
instance of a particular Oracle product or component. For example, in an Oracle Real
Application Clusters environment with Oracle ASM, each database instance, Oracle ASM
instance, and listener has an ADR home.