Which statement is true about InnoDB persistent index statistics?

• A. Execution plans based on transient index statistics improve precision when innodb_stats_persistent_sample_pages is increased.
• B. Index statistics are calculated from pages buffered in the buffer pool for tables with InnoDB storage engine.
• C. Setting innodb_stats_auto_recalc=ON causes statistics to be updated automatically when a new index is created.
• D. Updating index statistics is an I/O expensive operation.
• E. Increasing innodb_stats_persistent_sample_pages determines higher pages scanning speed, at the cost of increased memory usage.

Examine these InnoDB Cluster parameter settings:

Now examine the partial status:

A permanent network failure isolates host3.
Which two statements are true? (Choose two.)

• A. Failure of the instance deployed on host1 provokes an outage.
• B. The primary instance can be specified by using the command
  cluster.setPrimaryInstance(<host>:<port>).
• C. The issuing command cluster.switchToMuitiPrimaryMode() will fail to enable multi-primary mode.
• D. The instance deployed on host3 will automatically rejoin the cluster when connectivity is re-established.
• E. The instance deployed on host3 is expelled from the cluster and must be rejoined using cluster.addInstance ('host3:3377')
• F. The instance deployed on host2 is elected as the new primary instance.

You recently upgraded your MySQL installation to MySQL 8.0.
Examine this client error:

Which option will allow this client to connect to MySQL Server?

• A. ALTER USER user -
  IDENTIFIED WITH caching_sha2_password
  BY 'password';
• B. [mysqld]
  default_authentication_plugin=mysql_native_password
• C. [mysqld]
  default_authentication_plugin=sha256_password
• D. [mysqld]
  default_authentication_plugin=caching_sha2_password
• E. ALTER USER user -
  IDENTIFIED WITH mysql_native_password
  BY 'password';
• F. ALTER USER user -
  IDENTIFIED WITH sha256_password -
  BY 'password';

You execute this command:
shell> mysqlpump --exclude-databases=% --users
Which statement is true?

• A. It creates a logical backup of all MySQL user accounts.
• B. It creates a logical backup of only the users database.
• C. It returns an error because the mysqldump command should have been used.
• D. It creates a logical backup of all metadata, but contains no table data.