View the Exhibit and examine the parameter settings in your server-side parameter file
(SPFILE). When you tried to start the database instance, you received the following error:
SQL> startup
ORA-00824: cannot set SGA_TARGET or MEMORY_TARGET due to existing internal
settings, see alert log for more information
Why did the instance fail to start?
Exhibit:
A.
Because the PGA_AGGREGATE_TARGET parameter is not set
B.
Because the STATISTICS_LEVEL parameter is set to BASIC
C.
Because MEMORY_TARGET and MEMORY_MAX_TARGET cannot be equal
D.
Because both the SGA_TARGET and MEMORY_TARGET parameters are set.
Explanation:
Setting SGA Target Size
You enable the automatic shared memory management feature by setting the
SGA_TARGET parameter to a nonzero value. This parameter sets the total size of the SGA.
It replaces the parameters that control the memory allocated for a specific set of individual
components, which are now automatically and dynamically resized (tuned) as needed.
Note:
The STATISTICS_LEVEL initialization parameter must be set to TYPICAL (the default) or
ALL for automatic shared memory management to function.
B is correct:
https://docs.oracle.com/cd/B14117_01/server.101/b10755/initparams208.htm
Setting the STATISTICS_LEVEL parameter to BASIC disables the collection of many of the important statistics required by Oracle Database features and functionality, including:
Automatic Workload Repository (AWR) Snapshots
Automatic Database Diagnostic Monitor (ADDM)
All server-generated alerts
Automatic SGA Memory Management
Automatic optimizer statistics collection
Object level statistics
End to End Application Tracing (V$CLIENT_STATS)
Database time distribution statistics (V$SESS_TIME_MODEL and V$SYS_TIME_MODEL)
Service level statistics
Buffer cache advisory
MTTR advisory
Shared pool sizing advisory
Segment level statistics
PGA Target advisory
Timed statistics
Monitoring of statistics
Note:
Oracle strongly recommends that you do not disable these important features and functionality.