Oracle认证考试1z0-883章节练习(2018.11.07)

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

Consider the following table:

Which method should used to add a new g201305 partition to the table?（）

You have a login-path named "adamlocal" that was created by using the mysql_config_editor command. You need to check what is defined for this login_path to ensure that it is correct for you deployment.
You execute this command:
$mysql_config_editor print –login-path=adamlocal What is the expected output of this command?（）

Consider the query:
Mysql＞ SET @run = 15;
Mysql＞ EXPLAIN SELECT objective, stage, COUNT (stage)
FROM iteminformation
WHERE run=@run AND objective=’7.1’
GROUP BY objective,stage
ORDER BY stage;

The iteminformation table has the following indexes;
Mysql＞ SHOW INDEXES FROM iteminformation:

This query is run several times in an application with different values in the WHERE clause in a growing data set.
What is the primary improvement that can be made for this scenario?（）

You want to start monitoring statistics on the distribution of storage engines that are being used and the average sizes of tables in the various databases.
Some details are as follows:
The Mysql instance has 400 databases. Each database on an average consists of 25-50 tables. You use the query:
SELECT TABLE_SCHEMA, 'ENGINE', COUNT (*), SUM(data_length) total_size FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE= 'BASE TABLE' GROUP BY TABLE_SCHEMA, 'ENGINE' ;
Why is this query slow to execute?（）

Full Atomicity, Consistency, Isolation, Durability (ACID) compliance is a necessity for a new application, which heavily reads and writes data.
This requires the following config file options: Sync_binlog=1 Innodb_flush_log_at_trx_commit=1 Innodb_doublewrite=1 However, this configuration is expected to introduce disk I/O overhead.
What three changes will reduce disk I/O overheads?（）