1z0-883
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
题目
InnoDB uses row and table-level locks, but row locks are not escalates
InnoDB locks only those rows that are updated
InnoDB only uses row locks, not page or table-level locks
InnoDB row locks may be escalated to page or table-level locks
InnoDB uses row-level or table-level locks depending on the number of rows affected
相似问题和答案
第1题：
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2题：
A.因为InnoDB在一个日志中保存到所有主键的指针，短的主键使日志小
B.因为InnoDB使用主键定位二级索引，短的主键使查询快
C.因为InnoDB使用主键定位表记录，短的主键使查询快
D.因为InnoDB使用主键定位表，短的主键使查询快
第3题：
View the Exhibit exhibit1 to examine the series of SQL commands. View the Exhibit exhibit2 to examine the plans available in the SQL plan baseline. The baseline in the first row of the Exhibit is created when OPTIMIZER_MODE was set to FIRST_ROWS.Which statement is true if the SQL query in exhibit1 is executed again when the valueof OPTIMIZER_MODE is set to FIRST_ROWS?（）
A. The optimizer uses a new plan because none of the plans in the exhibit2 are fixed plans.
B. The optimizer uses the plan in the second row of the exhibit2 because it is an accepted plan.
C. The optimizer uses the plan in the first row of the exhibit2 because it is the latest generated plan.
D. The optimizer uses the plan in the first row of the exhibit2 because OPTIMIZER_MODE was set to FIRST_ROW during its creation.
第4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.
正确答案:A
第5题：
简述MyISAM与innoDB存储引擎有何差别？
正确答案: A.两者在文件构成上有区别；
B.InnoDB支持事务处理，MyISAM不支持；
C.对无WHERE子句的COUNT（*）操作的不同：MyISAM中保存了该值，直接读取，InnoDB需要作全表扫描；
D.锁的区别：InnoDB支持表级锁和行级锁，MyISAM只支持表级锁；
E.索引会缓存数据，而MYISAM不会；
F.INNODB不区分char和varchar；
G.INNODB支持hash索引，而MYISAM不支持；
H.InnoDB不支持FULLTEXT类型的索引；
I.InnoDB 中不保存表的具体行数，也就是说，执行select count（*） from table时，InnoDB要扫描一遍整个表来计算有多少行，但是MyISAM只要简单的读出保存好的行数即可。注意的是，当count（*）语句包含
W.here条件时，两种表的操作是一样的；
J.对于AUTO_INCREMENT类型的字段，InnoDB中必须包含只有该字段的索引，但是在MyISAM表中，可以和其他字段一起建立联合索引；
K.DELETE FROM table时，InnoDB不会重新建立表，而是一行一行的删除；
L.LOAD TABLE FROM
M.ASTER操作对InnoDB是不起作用的，解决方法是首先把InnoDB表改成MyISAM表，导入数据后再改成InnoDB表，但是对于使用的额外的InnoDB特性（例如外键）的表不适用。
第6题：
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：
Onboard a Ro-Ro vessel many decks are used for the carriage of both rolling and container cargoes，as such it is most useful if a deck socket accepts both ______．
A.Twist-Locks and lashing hooks
B.Container locks and bridge fittings
C.Bridge fittings and lashing hooks
D.Twist-locks and container locks
第8题：
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9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.
正确答案:A,D
第10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
正确答案:B