Buffers表示的是（）。A、缓冲区B、句柄C、浏览D、备份

题目

Buffers表示的是（）。

A、缓冲区
B、句柄
C、浏览
D、备份

相似考题

2.Oracle数据中,下列哪些等待事件将产生大量的IO?()A.log file parallel writeB.latch：cache buffers chainsC.db file sequential readD.db file scattered read

3.V2监控系统监控运行窗口遥测值趋势曲线无反应，可删除（）进行处理A、project/Buffers/hcurveDefineB、project/mapfileC、project/supportD、project/graph

4.Which three statements are true about memory buffer allocation by a MySQL Server?()A.Global buffers such as the InnoDB buffer pool are allocated after the server starts, and are never freedB.Thread buffers are allocated when a client connects, and are freed when the client disconnectsC.Buffers that are needed for certain operation are allocated when the operation starts, and freed when it endsD.User buffers are allocated at server startup and freed when the user is droppedE.All dynamic buffers that are set with a SET GLOBAL statement immediately get allocated globally, and are never freed

更多“Buffers表示的是（）。”相关问题

第1题：

CONFIG. SYS文件中常用的命令有（）
- A、 DOS内部命令
- B、 DOS外部命令
- C、 BUFFERS命令
- D、 FILES命令
正确答案:C,D
第2题：

查看路由器上的所有保存在flash中的配置数据应在特权模式下输入命令：（）
- A、DISPLAY running-config
- B、DISPLAY interface
- C、DISPLAY startup-config
- D、DISPLAY memory
- E、DISPLAY ip config
- F、DISPLAY buffers
正确答案:C
第3题：

What are two reasons for packet loss on a VoIP connection？（）
- A、serialization delay
- B、overrun
- C、full buffers and queues
- D、propagation delay
- E、shaping delay
- F、TCP header errors
正确答案:B,C
第4题：

Which three statements are true about memory buffer allocation by a MySQL Server?（）
- A、Global buffers such as the InnoDB buffer pool are allocated after the server starts, and are never freed
- B、Thread buffers are allocated when a client connects, and are freed when the client disconnects
- C、Buffers that are needed for certain operation are allocated when the operation starts, and freed when it ends
- D、User buffers are allocated at server startup and freed when the user is dropped
- E、All dynamic buffers that are set with a SET GLOBAL statement immediately get allocated globally, and are never freed
正确答案:A,B,C
第5题：

Which two statements about the background process of thedatabase writerare true（）
- A、It is possible to have multiple database writers in an Oracle instance.
- B、It writes dirty buffers， if any， to data files whenever a checkpoint occurs.
- C、It writes dirty buffers， if any， to data files whenever a transaction commits.
- D、It writes dirty buffers， if any， to data files before the log writer （LGWR） writes.
正确答案:A,B
第6题：

What is the solution for the "maximum socket buffer size" warnings in Oracle Coherence version 3.1 to 3.3 ？（）
- A、 configure the OS allow for larger buffers
- B、 upgrade the Coherence version
- C、 configure the OS allow for small buffers
- D、 configure the OS allow for small buffers and upgrade the Coherence version
正确答案:A
第7题：

多选题
Which two statements about the background process of thedatabase writerare true（）
A
It is possible to have multiple database writers in an Oracle instance.
B
It writes dirty buffers， if any， to data files whenever a checkpoint occurs.
C
It writes dirty buffers， if any， to data files whenever a transaction commits.
D
It writes dirty buffers， if any， to data files before the log writer （LGWR） writes.

正确答案： D,A
解析：数据库写进程(DBWn) 可以将缓冲区的内容写入数据文件。DBWn进程负责将数据库缓冲区高速缓存中经过修改的缓冲区（脏数据缓冲区）写入磁盘。虽然对于大多数系统来说，一个数据库写进程(DBW0) 已经足够，但如果系统需要频繁修改数据，则可以配置附加进程（DBW1到DBW9以及DBWa到DBWj）以改进写性能（A正确，可以有很多个dbwr进程）。这些附加DBWn进程在单处理器系统中没有用。
当数据库缓冲区高速缓存中的某个缓冲区被修改时，系统会将其标记为脏数据缓冲区，并将其添加到按SCN 顺序存放的灰数据缓冲区的LRUW（LRU 写）列表中。因此，该顺序与为这些更改的缓冲区写入重做日志的重做操作的顺序相匹配。当缓冲区高速缓存中的可用缓冲区的数量低于某个内部阈值（达到服务器进程发现很难获取可用缓冲区的程度）时，DBWn会将灰数据缓冲区写入数据文件，写入顺序与按照LRUW 列表的顺序修改灰数据缓冲区的顺序相同。 SGA 包含的内存结构具有重做流中的某个位置的重做字节地址(RBA)，当实例发生故障时，将从该位置开始恢复。此结构充当指向重做的指针，并且由CKPT 进程按照每三秒一次的频率写入控制文件。由于DBWn按照SCN 顺序写入灰数据缓冲区，而重做按照SCN 顺序执行，因此每当DBWn从LRUW 列表写脏数据缓冲区时，还会将SGA 内存结构中保持的指针前移，以便实例恢复（如果需要）从近似正确的位置开始读取重做，并避免不需要的I/O。这称为―增量检查点‖。
注：还有其它一些DBWn可能会执行写操作的情况，例如，当表空间被设置为只读或被置于脱机状态时。在这些情况下，不会出现增量检查点，因为仅属于相应数据文件的灰数据缓冲区在写入数据库时的顺序与SCN 顺序无关。
LRU 算法将更频繁访问的块保存在缓冲区高速缓存中，这样，在将缓冲区写入磁盘时，缓冲区不大可能包含将很快有用的数据。
DB_WRITER_PROCESSES初始化参数指定DBWn进程数。DBWn进程的最大数目为20。
如果用户在启动过程中未指定该进程数，Oracle DB 将根据CPU 和处理器组的数量来决定如何设置DB_WRITER_PROCESSES。
在以下情况下，DBWn进程将脏数据缓冲区写入磁盘：
• 当服务器进程在扫描阈值数目的缓冲区之后找不到干净的可重用缓冲区时，通知DBWn执行写操作。DBWn在执行其它处理的同时，将灰数据缓冲区异步写入磁盘。
•DBWn定期写缓冲区以推进检查点。检查点是重做线程（日志）中开始执行实例恢复的位置。该日志位置由缓冲区高速缓存中最旧的脏数据缓冲区确定。
在所有情况下，DBWn均执行成批（多块）写操作以提高效率。多块写操作中写入的块数因操作系统而异。 C答案：是LGWR进程
D答案：LGWR先记，DBWR后写。
LGWR 的写入速度通常足够快，可以确保缓冲区中始终有空间可供新条目使用，即使对重做日志的访问量很大时也是如此。LGWR 将缓冲区的一个连续部分写入磁盘。 LGWR 在以下情况下执行写操作： • 用户进程提交事务处理时
• 重做日志缓冲区的三分之一已满时 • 重做日志缓冲区达到1M的redo条目
• 在DBWn进程将经过修改的缓冲区写入磁盘（如果需要）之前 • 每隔3 秒
必须在与缓冲区更改相关联的所有重做记录写入磁盘后，DBWn才可以向磁盘写入经过修改的缓冲区（先行写协议）。
第8题：

单选题
Buffers表示的是（）。
A
缓冲区
B
句柄
C
浏览
D
备份

正确答案： D
解析：暂无解析
第9题：

单选题
You are analyzing the components of the redo log mechanisms in your Oracle database. Which of the following purposes does the CKPT process serve?（）
A
Writes buffers to disk
B
Writes current redo log number to datafile headers
C
Writes redo log information to disk
D
Reads information into memory for users

正确答案： A
解析：暂无解析
第10题：

单选题
Identify the memory component from which memory may be allocated for: （） 1: Session memory for the shared server 2: Buffers for I/O slaves 3: Oracle Database Recovery Manager (RMAN) backup and restore operations
A
Large Pool
B
Redo Log Buffer
C
Database Buffer Cache
D
Program Global Area （PGA）

正确答案： D
解析：暂无解析
第11题：

多选题
Which three statements are true about memory buffer allocation by a MySQL Server?（）
A
Global buffers such as the InnoDB buffer pool are allocated after the server starts, and are never freed
B
Thread buffers are allocated when a client connects, and are freed when the client disconnects
C
Buffers that are needed for certain operation are allocated when the operation starts, and freed when it ends
D
User buffers are allocated at server startup and freed when the user is dropped
E
All dynamic buffers that are set with a SET GLOBAL statement immediately get allocated globally, and are never freed

正确答案： A,B
解析：暂无解析
第12题：

多选题
What are the consequences of executing the SHUTDOWN ABORT command？（）
A
The database files are synchronized.
B
Uncommitted changes are not rolled back.
C
The database is closed， but the instance is still started.
D
Database buffers and redo buffers are not written to the disk.
E
The database undergoes automatic media recovery during the next startup.

正确答案： B,C
解析：暂无解析
第13题：

What are the consequences of executing the SHUTDOWN ABORT command？（）
- A、The database files are synchronized.
- B、Uncommitted changes are not rolled back.
- C、The database is closed， but the instance is still started.
- D、Database buffers and redo buffers are not written to the disk.
- E、The database undergoes automatic media recovery during the next startup.
正确答案:B,D
第14题：

Oracle数据中，下列哪些等待事件将产生大量的IO？（）
- A、log file parallel write
- B、latch：cache buffers chains
- C、db file sequential read
- D、db file scattered read
正确答案:C,D
第15题：

Which of the following events would not explain excessive CPU utilization？（）
- A、A large number of BGP sessions
- B、A large BGP table
- C、A router is configured with the following command： ip route 0.0.0.0 0.0.0.0 fa 0/1
- D、All interface buffers are continually in use
- E、A flapping interface
- F、The router sends a large number of ARP requests
正确答案:B
第16题：

Which two statements about the background process of the database writer are true（）
- A、It is possible to have multiple database writers in an Oracle instance.
- B、It writes dirty buffers， if any， to data files whenever a checkpoint occurs.
- C、It writes dirty buffers， if any， to data files whenever a transaction commits.
- D、It writes dirty buffers， if any， to data files before the log writer （LGWR） writes
正确答案:A,B
第17题：

Which background process is responsible for writing the dirty buffers from the write list to the data files during a checkpoint？（）
- A、CKPT
- B、SMON
- C、LGWR
- D、DBWn
- E、ARCn
正确答案:D
第18题：

在CONFIG.SYS中，用于设置磁盘缓冲区数的命令行为BUFFERS=n，其中n的取值范围为（）间的整数。
- A、1到99
- B、3到199
- C、0到99
- D、3到128
正确答案:A
第19题：

单选题
What is the solution for the "maximum socket buffer size" warnings in Oracle Coherence version 3.1 to 3.3 ？（）
A
configure the OS allow for larger buffers
B
upgrade the Coherence version
C
configure the OS allow for small buffers
D
configure the OS allow for small buffers and upgrade the Coherence version

正确答案： A
解析：暂无解析
第20题：

多选题
Which two statements about the background process of the database writer are true（）
A
It is possible to have multiple database writers in an Oracle instance.
B
It writes dirty buffers， if any， to data files whenever a checkpoint occurs.
C
It writes dirty buffers， if any， to data files whenever a transaction commits.
D
It writes dirty buffers， if any， to data files before the log writer （LGWR） writes

正确答案： D,B
解析：暂无解析
第21题：

多选题
Examine the details of the Top 5 Timed Events in the following Automatic Workloads Repository (AWR)report:What are three possible causes for the latch-related wait events?（）
A
The size of the shared pool is too small.
B
Cursors are not being shared.
C
A large number COMMITS are being performed.
D
There are frequent logons and logoffs.
E
The buffers are being read into the buffer cache, but some other session is changing the buffers.

正确答案： B,C
解析：暂无解析
第22题：

单选题
You executed the following command to start the database： SQL> STARTUP ORACLE instance started. Total System Global Area 281018368 bytes Fixed Size 789000 bytes Variable Size 229635576 bytes Database Buffers 50331648 bytes Redo Buffers 262144 bytes ORA-00205： error in identifying controlfile， check alert log for more info Which view would you query at this stage to investigate this missing control file？（）
A
V$INSTANCE
B
V$CONTROLFILE
C
DBA_CONTROL_FILES
D
V$DATABASE_PROPERTIES
E
V$CONTROLFILE_RECORD_SECTION

正确答案： D
解析：暂无解析
第23题：

单选题
Flushing dirty buffers out of the buffer cache is influenced to the greatest extent by which of the following process?（）
A
ARCH
B
SMON
C
LGWR
D
SERVER

正确答案： D
解析：暂无解析

Buffers表示的是（）。A、缓冲区B、句柄C、浏览D、备份

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