单选题 Four nodes are configured to use circular replication. Examine these configuration parameters for each each node:slave_parallel_type=DATABASE; slave_parallel_workers=4 slave_preserve_commit_order=0 Which statement is true?
A、Each slave thread is responsible for updating a specific database.
B、Cross - database constraints can cause database inconsistency.
C、Setting slave_parallel_type=DATABASE won't work for circular replication; it should be set to LOGICAL_CLOCK.
D、Increasing slave_parallel_workers will improve high availability.
E、Setting slave_preserve_commit_order to ON will improve data consistency.
F、Setting transaction_allow_batching to ON will improve data consistency.
单选题 Examine this partial output for InnoDB Cluster status: "topology" ; "host1:3377" : "address" ; "host1:3377" , "mode" : "R/W" ,..... "STATUS" : " ONLINE" , "version" ; "8.0.18" , "host1:3377" : "address" ; "host2:3377" , "mode" : "R/O" ,... ... "STATUS" : " MISSING" , "host1:3377" : "address" ; "host3:3377" , "mode" : "R/O" ,..... "STATUS" : " ONLINE" , "version" ; "8.0.18" Which statement explains the state of the instance deployed on host2?
A、It can rejoin the cluster by using the command cluster.addInstance ('<user>@host3:3377').
B、It has been expelled from the cluster because of a transaction error.
C、It can be recovered from a donor instance on host3 by cloning using the command cluster.rejoinInstance ('<user>@host3:3377').
D、It has been removed from the cluster by using the command STOP GROUP_REPLICATION;.
E、It can rejoin the cluster by using the command dba.rebootClusterFromCompleteOutage().
单选题 Choose the best answer.Four nodes are configured to use circular replication. Examine these configuration parameters for each each node:slave_parallel_type = DATABASE; slave_parallel_workers = 4 slave_preserve_commit_order = 0 Which statement is true?
A、Each slave thread is responsible for updating a specific database.
B、Cross - database constraints can cause database inconsistency.
C、Setting slave_parallel_type = DATABASE won't work for circular replication; it should be set to LOGICAL_CLOCK.
D、Increasing slave_parallel_workers will improve high availability.
E、Setting slave_preserve_commit_order to ON will improve data consistency.
F、Setting transaction_allow_batching to ON will improve data consistency.
单选题 What does the slave I/O thread do?
A、monitors and schedules I/O calls to the subsystem for the relay logs
B、connects to the master and requests it to send updates recorded in its binary logs
C、acquires a lock on the binary log for reading each event to be sent to the slave
D、reads the relay log and executes the events contained in them
单选题 Examine this command:shell> mysqldump --no - create - info --all - databases --result - file=dump.sql Which statement is true?
A、It will not write CREATE TABLESPACE statements.
B、It will not write CREATE LOGFILE GROUP statements.
C、It will not write CREATE DATABASE statements.
D、It will not write CREATE TABLE statements.
单选题 MySQL programs look for option files in standard locations.Which method will show the option files and the order in which they are read?
A、mysql> SHOW GLOBAL VARIABLES;
B、shell> mysql --print - defaults
C、shell> mysqladmin --debug
D、shell> mysqld --help --verbose
单选题 Examine this command, which executes successfully:$ mysqlbackup --user=dba --password --port=3306 --with - timestamp --only - known - file - types --backup - dir=/export/backups backup Which statement is true?
A、Only tables stored in their own tablespaces are backed up.
B、Only InnoDB data and log files are backed up.
C、Only non - encrypted files are backed up.
D、Only files for MySQL or its built - in storage engines are backed up.
E、The backup includes only data files and their metadata.