When you try to start the database instance with these parameter settings, you receive the following error message:

SQL > startup

ORA-00824: cannot set SGA_TARGET or MEMORY_TARGET due to existing internal settings, see alert log for more information.

Identify the reason the instance failed to start.

A. The PGA_AGGREGATE_TARGET parameter is set to zero.

B. The STATISTICS_LEVEL parameter is set to BASIC.

C. Both the SGA_TARGET and MEMORY_TARGET parameters are set.

D. The SGA_MAX_SIZE and SGA_TARGET parameter values are not equal.

STATISTICS_LEVEL

STATISTICS_LEVEL specifies the level of collection for database and operating system statistics. The Oracle Database collects these statistics for a variety of purposes, including making self-management decisions.

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

When the STATISTICS_LEVEL parameter is modified by ALTER SYSTEM, all advisories or statistics are dynamically turned on or off, depending on the new value of STATISTICS_LEVEL. When modified by ALTER SESSION, the following advisories or statistics are turned on or off in the local session only. Their system-wide state is not changed:

• Timed statistics

• Timed OS statistics

• Plan execution statistics

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