1Z0-873 試験問題を無料オンラインアクセス

When working with InnoDB, which of the following is true when trying to create foreign key references?

• A.Only the child column must be indexed.
• B.Only the parent column must be indexed.
• C.InnoDB may create an index automatically.
• D.InnoDB will not create an index automatically.
• E.Both the parent & child columns must be indexed.

With MyISAM table locking, deadlocks do not occur because:

• A.If a table is locked with a read lock and a write lock, the write lock is set before the read lock
• B.All tables to be locked are sorted in an internally defined order
• C.None of the above
• D.Tables are locked one table at a time until the thread gets all the locks

Which of the following describes how deadlocks may occur and how InnoDB resolves them?

• A.Deadlocks happen when two transactions both have locks that the other is waiting for the release of the lock that the other holds.
• B.InnoDB resolves deadlocks by terminating and rolling back one of the deadlocking transactions.
• C.InnoDB resolves deadlocks by terminating and rolling back both of the deadlocking transactions.
• D.Deadlocks happen anytime when more than one lock is placed in a table.

The MySQL server host crashes at 10:00 in the morning, and is brought back online at 10:30. In order to ensure that all data are consistent, a copy is first made of the table, tablespace and log files currently on the server host, and these files are then restored from a backup made at 03:00 the same morning. What should be done in order to bring the database to the state it was at just before the server host crashed?

• A.The mysql_restore utility should be used to update the server to its last known state.
• B.The binary logs recorded after the backup at 03:00 should be re-applied to make the database file consistent with the state just before the crash.
• C.The procedure described is wrong; instead, the mysqlcheck utility should be used and only if that fails should backup copies be restored.
• D.Once the backup files from 03:00 have been restored, there is nothing more that can be done to restore the database files.

When you acquire an advisory lock using GET_LOCK(), the lock is released if

• A.You issue a RELEASE_LOCK() statement
• B.None of the above
• C.Your connection to the server terminates
• D.You issue another GET_LOCK() statement