Question

MySQL
Multiple Choice
Answer as soon as possible

1. What does the pt-table-checksum tool do?
(a) It adds a column to every table in every database, that will be populated with the checksum of the row, so that when data is changed, the data can be verified when replicated.
(b) It calculates checksums on every table that can be used to compare a table on a master and slave to see if the data matches.
(c) It installs and runs a checksum plugin into MySQL to help enforce security during replication.
(d) None of the above.

2. What does the pt-table-sync tool do?
(a) Starts the slave in a special mode that does a 2-way sync, syncing data from master to slave and slave to master.
(b) Marks certain databases and tables for replication so that only changes on those databases and tables get replicated to the slave during normal replication.
(c) Compares the data in the master and slave tables and if differences are found, sends the changes to the slaves so that they will once again be in sync with the master.
(d) None of the above.

3. The pt-table-sync tool works by re-applying the required change to the master so that it can be replicated to all the slaves.
(a) True
(b) False

4. The pt-slave-find tool:
(a) When run on the slave will find that slave's master.
(b) When run on the master will find that master's slaves.
(c) Reconnects a slave to its master after a replication error.
(d) None of the above.

5. What do the --print and --execute options in the pt-table-sync tool?
(a) Normally the pt-table-sync tool syncs the data silently, you need the --print option to print the output as it executes.
(b) The --print option prints the changes what will be executed. The --execute option will executes those changes.
(c) None of the above.

Answer 1

2)Answer

a)Starts the slave in a special mode that does a 2-way sync, syncing data from master to slave and slave to master.

3)Answer

a)True.

pt-table-sync in this pt means percona tool kit. This tool is used to make the changes. It always makes the changes on the replication master, never the replication slave directly.