1Z0-874 Online Practice Questions and Answers

Which of the following best describes what the master.info file contains and how it is used?

A. It contains the values from the CHANGE MASTER statement.

B. When the slave restarts it looks for which master to use from this file.

C. It contains information about the master server, its slaves and its configuration.

D. It is used by an administrator to determine what slaves connect to the master, and other information about the master server.

How can the SHOW PROCESSLIST command be helpful when optimizing queries?

A. It shows if a query is using an index or not.

B. It shows how the server processes a query.

C. If checked periodically, it can reveal queries that cause other queries to hang.

D. It shows the percentage of processing power that each query is using on a server.

The account 'ulf'@'localhost' has previously been created with the statement GRANT ALL PRIVILEGES ON *.* TO 'ulf'@'localhost' IDENTIFIED BY 'w01f'

This account should no longer be used, so you issue the following command:

REVOKE ALL PRIVILEGES ON *.* FROM 'ulf'@'localhost'

After executing this statement, you inspect the server and find that no clients are connected using that account. However, the next day you notice that the account 'ulf'@'localhost' is indeed connected to the server.

Why is it still possible for the account 'ulf'@'localhost' to connect to the server?

A. Specifying GRANT ALL PRIVILEGES ON *.* effectively created an administrator account, which cannot be disabled through the REVOKE statement

B. The REVOKE statement used does not remove the USAGE privilege from the account, allowing new connections with that account.

C. The REVOKE command was not followed by a FLUSH PRIVILEGES command, so the account was never actually disabled

D. The ON *.* clause should not be specified when disabling an account

What type of resource limitations may be placed on a user account with the GRANT statement?

A. The number of times per hour that an account is allowed to connect to the server

B. The number of queries per hour an account is allowed to issue

C. The number of updates per hour an account is allowed to issue

D. The maximum number of simultaneous connections an account can have

E. Resource limits can only be specified globally, not per-account

F. MySQL does not have provisions for limiting resource usage

Granting access to the mysql database...

A. Should never be done for any users.

B. Should always be done for all users.

C. Should only be done on administrator accounts.

D. Should be done for anyone needing to create views

Why should you be selective when granting the SUPER privilege to an account?

A. Because it allows a client to kill other client connections.

B. Because it allows a client to shutdown the server.

C. Because it allows changing of the server runtime configuration.

D. Because it allows client accounts to takeover other client accounts.

mysql> EXPLAIN SELECT * FROM City WHERE CountryCode = 'USA'\G *************************** 1. row *************************** id: 1 select_type: SIMPLE table: City type: ALL possible_keys: NULL key: NULL

key_len: NULL ref: NULL rows: 4079 Extra: Using where What does it mean that the possible_keys column value is NULL?

A. No index is considered available for this query.

B. No index exists for the table you are querying.

C. You are not making use of any available indexes in your query.

Is it possible to force the join order in a query, and if so how?

A. No, it is not possible.

B. Yes it is possible, use SELECT STRAIGHT_JOIN rather than just SELECT, the list the tables in the desired order.

C. Yes it is possible use SELECT FORCE_JOIN rather than just SELECT, then list the tables in the desired order.

D. Yes it is possible simply list the tables in the desired order in your SELECT.

Which of the following best describe the effects on performance for the dynamic-row format for MyISAM has?

A. Retrievals are more complex and slower.

B. Retrievals are less complex and are faster.

C. Rows generally take up less disk space than fixed-row format.

D. Rows generally take up more disk space than fixed-row format.

Which of the following best describes the purpose of the join buffer, and when should you increase the size of it?

A. The join buffer is used to process joins.

B. The join buffer is set per-connection.

C. The join buffer is global and can only be changed by restarting the server.

D. The value should be increased if the client performs a lot of SELECT operations.

E. The join buffer is used to process sorts when complex joins are being performed.

F. The value should be increased if the client has the tendency to perform complex joins.