多选题Which three tasks can be performed by using the performance Schema?（）AFinding queries that are not using indexesBFinding rows that are locked by InnoDBCFinding client connection attributesDFinding the part of a code in which a single query is spending

第1题：

第2题：

Which three functions are performed by the SQL Tuning Advisor?（） (Choose three.)

• A、Building the SQL profile
• B、Recommending optimization of materialized views
• C、Checking query objects for missing and stale statistics
• D、Recommending bitmap, function-based, and B-tree indexes
• E、Recommending restructuring SQL queries that are using bad plans

正确答案:A,C,E

第3题：

A warehouse fact table in your Oracle 12c Database is range-partitioned by month and accessed frequently with queries that span multiple partitions The table has a local prefixed, range partitioned index. Some of these queries access very few rows in some partitions and all the rows in other partitions, but these queries still perform a full scan for all accessed partitions. This commonly occurs when the range of dates begins at the end of a month or ends close to the start of a month. You want an execution plan to be generated that uses indexed access when only a few rows are accessed from a segment, while still allowing full scans for segments where many rows are returned. Which three methods could transparently help to achieve this result?（）

• A、Using a partial local Index on the warehouse fact table month column with indexing disabled to the table partitions that return most of their rows to the queries.
• B、Using a partial local Index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.
• C、Using a partitioned view that does a UNION ALL query on the partitions of the warehouse fact table, which retains the existing local partitioned column.
• D、Converting the partitioned table to a partitioned view that does a UNION ALL query on the monthly tables, which retains the existing local partitioned column
• E、Using a partial global index on the warehouse fact table month column with indexing disabling for the table partitions that return most of their rows to the queries.
• F、Using a partial global index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.

正确答案:B,C,F

第4题：

Which three statements about subqueries are true?（）

• A、A single row subquery can retrieve only one column and one row.
• B、A single row subquery can retrieve only one row but many columns.
• C、A multiple row subquery can retrieve multiple rows and multiple columns.
• D、A multiple row subquery can be compared by using the ">" operator.
• E、A single row subquery can use the IN operator.
• F、A multiple row subquery can use the "=" operator.

正确答案:B,C,D

第5题：

Which three tasks can be performed using a duplicate database? （）(Choose three.)

• A、Testing the backup and recovery procedures
• B、Testing the upgrade of an Oracle database to a new release
• C、Testing the effect of an application changes on database performance
• D、Continuously updating archive log files from the target database to support failover

正确答案:A,B,C

第6题：

Which two operations can be performed on an external table（）

• A、Create a view on the table.
• B、Create an index on the table.
• C、Create a synonym on the table.
• D、Add a virtual column to the table.
• E、Update the table using the UPDATE statement.
• F、Delete rows in the table using the DELETE command

正确答案:A,C

第7题：

Which three tasks can be performed using a duplicate database？（）

• A、 Testing the backup and recovery procedures
• B、 Testing the upgrade of an Oracle database to a new release
• C、 Testing the effect of an application changes on database performance
• D、 Continuously updating archive log files from the target database to support failover

正确答案:A,B,C

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第14题：

Which three functions are performed by the SQL Tuning Advisor?（）

• A、Building and implementing SQL profiles
• B、Recommending the optimization of materialized views
• C、Checking query objects for missing and stale statistics
• D、Recommending bitmap, function-based, and B-tree indexes
• E、Recommending the restructuring of SQL queries that are using bad plans

正确答案:A,C,E

第15题：

Consider the events_% tables in performance Schema. Which two methods will clear or reset the collected events in the tables?（）

• A、Using DELETE statements, for example, DELETE FROM performance_schema.events_watis_current
• B、Using the statement RESET PERFORMANCE CACHE
• C、Using the statement FLUSH PERFORMANCE CACHE
• D、Using TRUNCATE statements, for example, TRUNATE TABLE performance_schema.events_waits_current
• E、Disabling and re-enabling all instruments
• F、Restarting Mysql

正确答案:D,F

第16题：

Which two operations can be performed on an external table（）

• A、Create a view on the table.
• B、Create an index on the table.
• C、Create a synonym on the table.
• D、Add a virtual column to the table.
• E、Update the table using the UPDATE statement.
• F、Delete rows in the table using the DELETE command.

正确答案:A,C

第17题：

Which three functions are performed by the SQL Tuning Advisor？（） 

• A、 Building the SQL profile
• B、 Recommending optimization of materialized views
• C、 Checking query objects for missing and stale statistics
• D、 Recommending bitmap， function-based， and B-tree indexes
• E、 Recommending restructuring SQL queries that are using bad plans

正确答案:A,C,E

第18题：

Which three tasks can be performed by using the performance Schema?（）

• A、Finding queries that are not using indexes
• B、Finding rows that are locked by InnoDB
• C、Finding client connection attributes
• D、Finding the part of a code in which a single query is spending time
• E、Finding the size of each table

正确答案:A,B,C

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