Oracle 1Z0-888 問題集

質問 1：
Consider:

What does the range value in the type column mean?
A. You can use an index and return rows that fall within a range of values.
B. The table will be scanned over a certain range of values.
C. This type of index uses the range hash.
D. There is a range of indexes that can be used.
正解：C

質問 2：
You have successfully provisioned the latest MySQL 5.7 database instance on a physical host, to be added to an existing farm for use in a modern, high volume, ACID-compliant, OLTP website, which serves hundreds of DML transactions per second.
The default values of which two key variables do you change to ensure seamless operation of the database? (Choose two.)
A. InnoDB Redo Log Size
B. Buffer Pool Size
C. Binary Log Size
D. Sort Buffer size
E. Key Buffer Size
F. Query Cache Size
正解：D,E

質問 3：
Which two statements are true regarding MySQL security? (Choose two.)
A. The mysql user needs to have sudo privileges.
B. The mysqld process should be run as root or administrator.
C. The mysqld process should not be run as root or administrator.
D. The root or administrator users should own all files and directories to which the server writes.
E. The mysqld process owner should own all files and directories to which the server writes.
正解：C,D

質問 4：
An administrator installs MySQL to run under a mysql OS account. The administrator decides to disable logins to the mysql account by using /nologin or /bin/false as the user's shell setting.
Which statement is true?
A. This prevents mysqld from starting when standard startup scripts are used.
B. The OS needs to allow logging in as mysql so that administrative tasks can be performed.
C. The mysql user needs a login and its home directory must be the base directory of the installation.
D. This prevents creation of a command shell with the mysql account, while allowing mysqld to run.
正解：C

質問 5：
You inherited a busy InnoDB OLTP Instance with 100 schemas and 100 active users per schema.
* Total dataset size is 200G with an average schema size of 2G.
* The data is transient and is not backed up and can be repopulated easily.
* Performance and responsiveness of the DB is paramount.
* The query pattern for the DB instance is split 90/10 read/write.
* DB host is dedicated server with 256G RAM and 64 cores.
One of your colleagues made some recent changes to the system and users are now complaining of performance impacts.
Which four configuration file edits might your colleague have performed to cause the negative DB performance? (Choose four.)
A. innodb_buffer_pool_size=200G
log_bin=mysql -bin
B. innodb_flush_method=O_DIRECT
C. max_heap_table_size = 2G
tmp_table_size=2G
D. sync_binlog=10
E. Innodb_flush_log_at_trx_commit=1
F. table_open_cache = 64
innodb_buffer_pool_instances=64
G. query_cache_size = 2G
query_cache_enabled=1
H. innodb_flush_log_at_trx_commit=0
正解：A,B,F,G