单选题What is true regarding InnoDB locking?（）A InnoDB uses row and table-level locks, but row locks are not escalatesB InnoDB locks only those rows that are updatedC InnoDB only uses row locks, not page or table-level locksD InnoDB row locks may be escalate

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第2题：

简述MyISAM与innoDB存储引擎有何差别？

第3题：

How does DB2 protect the integrity of indexes when data is updated?（）

• A、Locks are acquired on the data.
• B、Locks are acquired on index keys.
• C、Locks are acquired on index pages.
• D、Locks are acquired on index pointers.

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.

第5题：

Following a server crash, the automatic recovery of InnoDB fails. How would you begin to manually repair the InnoDB tables?（）

• A、Start the server with the – innodb_recover_options option set to FORCE
• B、Start the server with the – innodb_force_recovery option set to a non-zero value
• C、Start the server as usual, and then execute the REPAIR TABLE command
• D、Start the server as usual, and then execute the CHECK TABLE command

第6题：

Which two statements are true about InnoDB auto-increment locking?（）

• A、The auto-increment lock can be a table-level lock
• B、InnoDB never uses table-level locks
• C、Some settings for innodb_autoinc_lock_mode can help reduce locking
• D、InnoDB always protects auto-increment updates with a table-level lock

第7题：

The InnoDB engine has a feature known as clustered indexes. Which three statements are true about clustered indexes as used in InnoDB?（）

• A、A primary key must exist for creation of a clustered index
• B、A clustered index allows fulltext searching within InnoDB
• C、The first unique index is always used as a clustered index and not a primary key
• D、A clustered index provides direct access to a page containing row data
• E、If no indexes exist, a hidden clustered index is generated based on row IDs
• F、A primary key is used as a clustered index
• G、A clustered index is a grouping of indexes from different tables into a global index for faster searching

第8题：

Which two statements are true regarding single row functions?（）

• A、They accept only a single argument 
• B、They can be nested only to two levels 
• C、Arguments can only be column values or constants 
• D、They always return a single result row for every row of a queried table 
• E、They can return a data type value different from the one that is referenced

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第14题：

Which two of statements are true？（）

• A、It is possible to synchronize static methods.
• B、When a thread has yielded as a result of yield（）， it releases its locks.
• C、When a thread is sleeping as a result of sleep（）， it releases its locks.
• D、The Object.wait（） method can be invoked only from a synchronized context.
• E、The Thread.sleep（） method can be invoked only from a synchronized context.
• F、When the thread scheduler receives a notify（） request， and notifies a thread， that thread immediately releases its lock.

第15题：

Which of the following best describes how locks are used in DB2?（）

• A、To maintain control of updated rows for commit processing
• B、To ensure only committed changes are altered by another application
• C、To allow two applications to update the same row of data simultaneously
• D、To prevent multiple applications from accessing the same data simultaneously

第16题：

What is true regarding InnoDB locking?（）

• A、InnoDB uses row and table-level locks, but row locks are not escalates
• B、InnoDB locks only those rows that are updated
• C、InnoDB only uses row locks, not page or table-level locks
• D、InnoDB row locks may be escalated to page or table-level locks
• E、InnoDB uses row-level or table-level locks depending on the number of rows affected

第17题：

User Scott has updated the salary of one of the employees in the EMPLOYEES table and has not committed the transaction. What are the two types of locks that this scenario would lead to？（）

• A、null lock on the row being updated
• B、null lock on the table containing the row
• C、ROW SHARE lock for the row being updated
• D、ROW EXCLUSIVE lock for the row being updated
• E、shared row-exclusive lock for the row being updated
• F、a shareable table lock for the table containing the row
• G、exclusive table-level lock for the table containing the row

第18题：

Which two statements describe good practices for an application developer to reduce lockingconflicts in Oracle database（）

• A、Avoid coding unnecessary long-running transactions.
• B、Allow the database to handle locks in default locking mode.
• C、Always explicitly code the locks as per the requirement of the application.
• D、Allow escalation of row locks to block locks if too many row locks cause problem.

第19题：

A SQL Azure database generates an error when a row is inserted into any table in the database.  No error is generated when a row is deleted.  You need to recommend an approach for locating the source of the errors.  What should you recommend？（）  

• A、 Use a Dynamic Management View to check for locks.
• B、 Use a Dynamic Management View to check for blocked queries.
• C、 Use a Dynamic Management View to check for long-running queries.
• D、 Use a Dynamic Management View to check the size and maximum size of the database.

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