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 byORACLE_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.