Which two statements are true about the Automatic Diagnostic Repository (ADR)? (Choose two.)
A.
The ADR base keeps all diagnostic information in binary format
B.
SQL*Plus provides the ADRI script, which can be used to work with ADR
C.
The ADR can be used for problem diagnosis only when the database is open
D.
The ADR can be disabled by settting the DIAGNOSTIC_DEST parameter to null
E.
The ADR can be used for problem diagnosis even when the database instance is down
F.
The ADR base is shared across multiple instances
Explanation:
Automatic Diagnostic Repository (ADR)
The ADR is a file-based repository for database diagnostic data such as traces, dumps, the alert log, health monitor reports, and more. It has a unified directory structure across multiple instances and multiple products. Beginning with Release 11g, the database, Oracle Automatic Storage Management (Oracle ASM), the listener, and other Oracle products or components store all diagnostic data in the ADR. Each instance of each product stores diagnostic data underneath its own home directory within the ADR. For example, in an Oracle Real Application Clusters environment with shared storage and Oracle ASM, each database instance and each Oracle ASM instance has an ADR home directory. ADR’s unified directory structure, consistent diagnostic data formats across products and instances, and a unified set of tools enable customers and Oracle Support to correlate and analyze diagnostic data across multiple instances.
Note:
Beginning with Release 11g of Oracle Database, because all diagnostic data, including the alert log, are stored in the ADR, the initialization parameters BACKGROUND_DUMP_DEST and USER_DUMP_DEST are deprecated. They are replaced by the initialization parameter DIAGNOSTIC_DEST, which identifies the location of the ADR.
The Automatic Diagnostic Repository (ADR) is a directory structure that is stored outside of the database. It is therefore available for problem diagnosis when the database is down.
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.