1Z0-052 · Question #68
View the Exhibit to examine the output produced by the following query at three different times since the database instance started and has experienced workloads of different capacities: SQL> SELECT…
The correct answer is C. The database instance has the MEMORY_TARGET value set to a nonzero value. When V$MEMORY_DYNAMIC_COMPONENTS shows both SGA and PGA subcomponents with fluctuating current sizes across different workloads, it indicates Automatic Memory Management (MEMORY_TARGET) is active and Oracle is resizing both pools dynamically.
Question
View the Exhibit to examine the output produced by the following query at three different times since the database instance started and has experienced workloads of different capacities:
SQL> SELECT substr(component, 0, 10) COMP, current_size CS, user_specified_size US FROM v$memory_dynamic_components WHERE current_size!=0; What do you infer from this?
Exhibit
Options
- AThe database instance is running with manual PGA management.
- BThe database instance is running with manual shared memory management.
- CThe database instance has the MEMORY_TARGET value set to a nonzero value.
- DAll sessions are connected to the database instance in dedicated mode, and no RMAN or parallel
How the community answered
(50 responses)- A10% (5)
- B14% (7)
- C72% (36)
- D4% (2)
Why each option
When V$MEMORY_DYNAMIC_COMPONENTS shows both SGA and PGA subcomponents with fluctuating current sizes across different workloads, it indicates Automatic Memory Management (MEMORY_TARGET) is active and Oracle is resizing both pools dynamically.
Under manual PGA management (PGA_AGGREGATE_TARGET=0), PGA components are not dynamically sized by Oracle and would not appear with changing values in V$MEMORY_DYNAMIC_COMPONENTS.
Manual shared memory management means the SGA parameters are statically set and Oracle does not resize SGA components dynamically; V$MEMORY_DYNAMIC_COMPONENTS would show static or minimal changes rather than workload-driven fluctuations.
V$MEMORY_DYNAMIC_COMPONENTS tracks all memory components Oracle manages automatically. When MEMORY_TARGET is set to a nonzero value, Oracle's Automatic Memory Management controls both the SGA and PGA aggregate, resizing individual components such as buffer cache, shared pool, and PGA in response to workload demand. The fact that current_size values differ across three snapshots taken under different workload capacities is characteristic of AMM dynamically redistributing memory between components, which only occurs when MEMORY_TARGET is active.
The connection mode (dedicated vs. shared server) and RMAN parallel operations are unrelated to the dynamic memory resizing behavior visible in V$MEMORY_DYNAMIC_COMPONENTS.
Concept tested: Automatic Memory Management via MEMORY_TARGET parameter
Source: https://docs.oracle.com/en/database/oracle/oracle-database/19/admin/managing-memory.html#GUID-38F46564-DC31-4EBF-9F02-3D8B7E8FF2F8
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