29.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.
Answer: AC
关于Oracle数据库11g中的自动诊断信息库（ADR）哪两个陈述是真实的?
Automatic Diagnostic Repository. A a file-based hierarchical data store for managing diagnostic information, including network tracing and logging.
A. A single ADR can support multiple ADR homes for different database instances.
单个的自动诊断信息库可以支持多个用于不同的数据库实例的自动诊断信息库家目录。
C. If the environmental variable ORACLE_BASE is set, then DIAGNOSTIC_DEST is set to $ORACLE_BASE.
如果ORACLE_BASE环境变量已设置，则DIAGNOSTIC_DEST被设置为$ORACLE_BASE
参考：http://docs.oracle.com/cd/E11882_01/server.112/e25494/diag.htm#ADMIN11008
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_BASEis set,DIAGNOSTIC_DESTis set to the directory designated byORACLE_BASE. -
If environment variable
ORACLE_BASEis not set,DIAGNOSTIC_DESTis set to ORACLE_HOME/logWithin 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.