You notice that the performance of your production 24/7 Oracle 12c database has significantly degraded. Sometimes you are not able to connect to the instance because it hangs. You do not want to…

Question

Options

• AEnable Memory Access Mode, which reads performance data from SGA.
• BUse emergency monitoring to fetch data directly from SGA for analysis.
• CRun Automatic Database Diagnostic Monitor (ADDM) to fetch information from the latest
• DUse Active Session History (ASH) data and hang analysis in regular performance monitoring,
• ERun ADDM in diagnostic mode.

• A
  24% (9)
• B
  57% (21)
• C
  3% (1)
• D
  11% (4)
• E
  5% (2)

Explanation

Emergency monitoring is the correct approach because it bypasses the normal Oracle listener and connection mechanisms entirely, reading performance data directly from the SGA (System Global Area) in memory. This works even when the instance is hanging and regular connections are refused - Oracle Enterprise Manager's emergency monitoring mode uses OS-level memory access, making it the only option that functions under these exact conditions.

Why the distractors are wrong:

• A describes the mechanism behind emergency monitoring (SGA reads), but "Memory Access Mode" is not the correct Oracle feature name - this is a distractor that conflates the method with the feature.
• C requires ADDM to run normally against AWR snapshots, which demands a responsive database connection - unavailable when the instance hangs.
• D implies regular performance monitoring channels (ASH, hang analysis via EM), which also require a working connection and are therefore blocked by the hang.
• E "diagnostic mode" for ADDM is not a real Oracle 12c feature; ADDM has no special mode that bypasses connectivity requirements.

Memory tip: Think of B as the "break glass in emergency" option - when the database door is locked (hung), emergency monitoring climbs in through the window (direct SGA memory access) to see what's wrong inside.

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