You have a MySQL system with 500 GB of data that needs frequent backups.
You use a mix of MyISAM and InnoDB storage engines for your data. Examine your backup requirement:
* The MySQL system being backed up can never be unavailable or locked to the client applications.
* The recovery from the backup must work on any system.
* Only 1 hour of data can be lost on recovery of the backup.
Which option fulfills all backup requirements?

Examine these statements, which execute successfully:
CREATE ROLE r_world_rd;
GRANT SELECT ON world.* TO r_world_rd;
CREATE USER john IDENTIFIED BY 'P@ssw0rd';
GRANT r_world_rd TO john;
Examine these statements issued by user John:

What is the reason for the error?

Examine this statement, which executes successfully:

You want to improve the performance of this query:

Which change enables the query to succeed while accessing fewer rows?

An attempt to recover an InnoDB Cluster fails.
Examine this set of messages and responses:
host3:3377 ssl JS > dba.rebootClusterFromCompleteOutage() Reconfiguring the default cluster from complete outage...
The instance 'host1:3377'' was part of the cluster configuration. Would you like to rejoin it to the cluster? [y/N]: y The instance 'host2:3377' was part of the cluster configuration. Would you like to rejoin it to the cluster? [y/N]: y Dba.rebootClusterFromCompleteOutage: The active session instance isn't the most updated in comparison with the ONLINE instances of the Cluster's metadat a. Please use the most up to date instance: 'host1:3377'. (RuntimeError) Which statement is true?

Which two are contained in the InnoDB system tablespace (ibdata1) by default? (Chose two.)