Optimizer statistics are collected automatically.
Only timed operating system （OS） statistics and plan execution statistics are collected.
The snapshots for the Automatic Workload Repository （AWR） are not generated automatically.
Snapshots cannot be collected manually by using the DBMS_WORKLOAD_REPOSITORY package.
The Oracle server dynamically generates the necessary statistics on tables as part of query optimization.
第1题：
Examine the parameter for your database instance:You generated the execution plan for the following query in the plan table and noticed that the nested loop join was done. After actual execution of the query, you notice that the hash join was done in the execution plan:Identify the reason why the optimizer chose different execution plans.（）
A. The optimizer used a dynamic plan for the query.
B. The optimizer chose different plans because automatic dynamic sampling was enabled.
C. The optimizer used re-optimization cardinality feedback for the query.
D. The optimizer chose different plan because extended statistics were created for the columns used.
第2题：
The database instance has the following parameter setting： OS_AUTHENT_PREFIX = OPS$ OS_ROLES = FALSE REMOTE_OS_AUTHENT = FALSE REMOTE_OS_ROLES = FALSE TIMED_OS_STATISTICS = 0 You have a local operating system user SKD. You create a database user OPS$SKD， and then assignexternal authentication. The user OPS$SKD has the CREATE SESSION privilege. What would youachieve by the above process（）
第3题：
A. setting the STATISTICS_LEVEL parameter to TYPICAL
B. adding filters to the Automatic Database Diagnostic Monitor (ADDM)
C. enabling Automated Maintenance Task using Oracle Enterprise Manager
D. setting the OPTIMIZER_USE_PENDING_STATISTICS parameter to TRUE
第4题：
In your running instance， some of the initialization parameters are set as shown below： SGA_MAX_SIZE = 14GB DB_CACHE_SIZE = 1GB SHARED_POOL_SIZE = 3GB STATISTICS_LEVEL = BASIC PGA_AGGREGATE_TARGET = 0 You plan to enable Automatic Shared Memory Management but you are not able to set SGA_TARGET to a nonzero value. What could be the reason？（）
第5题：
In your database，the STATISTICS_LEVEL initialization parameter is set to BASIC. What is the impact of this setting？（）
第6题：
Your database is functional with peak load for one hour. You want to preserve the performance statistics collected during this period so that they can be used for comparison while analyzing the performance of the database in the future. What action would you take to achieve this task？（）
第7题：
Examine the parameter for your database instance: You generated the execution plan for the following query in the plan table and noticed that the nested loop join was done. After actual execution of the query, you notice that the hash join was done in the execution plan: Identify the reason why the optimizer chose different execution plans.（）
第8题：
You are connected to a pluggable database (PDB) as a common user with DBA privileges.The STATISTICS_LEVEL parameter is PDB_MODIFIABLE. You execute the following:SQL > ALTER SYSTEM SET STATISTICS_LEVEL = ALL SID = ‘*’ SCOPE = SPFILE;Which is true about the result of this command?（）
A. The STATISTICS_LEVEL parameter is set to all whenever this PDB is re-opened.
B. The STATISTICS_LEVEL parameter is set to ALL whenever any PDB is reopened.
C. The STATISTICS_LEVEL parameter is set to all whenever the multitenant container database (CDB) is restarted.
D. Nothing happens; because there is no SPFILE for each PDB, the statement is ignored.
第9题：
Which setting enables the baselines by default in Oracle Database 11g？（）
第10题：
You want to enable automatic PGA memory management in your database. Which setting is required to achieve this?（）