Oracle Oracle Certifications 1Z0-908 Questions & Answers

• Question 61:

  Your MySQL server was upgraded from an earlier major version.

  The sales database contains three tables, one of which is the transactions table, which has 4 million rows.

  You are running low on disk space on the datadir partition and begin to investigate.

  Examine these commands and output:

  

  Which two statements are true? (Choose two.)

  A. Executing SET GLOBAL innodb_row_format=COMPRESSED and then ALTER TABLE transactions will free up disk space.

  B. Executing ALTER TABLE transactions will enable you to free up disk space.

  C. Truncating the sales and leads table will free up disk space.

  D. Truncating the transactions table will free up the most disk space.

  E. The transactions table was created with innodb_file_per_table=OFF.

  Correct Answer: AE

• Question 62:

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

  A. table data

  B. primary indexes

  C. user privileges

  D. InnoDB Data Dictionary

  E. change buffer

  F. doublewrite buffer

  Correct Answer: DF

  Reference: https://docs.oracle.com/cd/E17952_01/mysql-5.7-en/innodb-system- tablespace.html

• Question 63:

  Which three settings control global buffers shared by all threads on a MySQL server? (Choose three.)

  A. sort_buffer_size

  B. key_buffer_size

  C. table_open_cache

  D. read_buffer_size

  E. innodb_buffer_pool_size

  F. tmp_table_size

  Correct Answer: ABF

  Reference: https://docs.oracle.com/cd/E17952_01/mysql-5.7-en/server-system- variables.html

• Question 64:

  Binary log events for the `mydb1' schema must be copied to a different schema name `mydb2'. Which command will do this?

  A. mysqlbinlog --rewrite-db='mydb1->mydb2' | mysql

  B. mysqlbinlog --datebase=mydb1 --database=mydb2 | mysql

  C. mysqlbinlog --rewrite-db='mydb1' --rewrite-db='mydb2' | mysql

  D. mysqlbinlog --read-from-remote-server --raw | sed `s/mydb1/mydb2/g' | mysql

  Correct Answer: D

• Question 65:

  You have upgraded the MySQL binaries from 5.7.28 to 8.0.18 by using an in-place upgrade. Examine the message sequence generated during the first start of MySQL 8.0.18:

  

  Which step or set of steps will resolve the errors?

  A. Remove the redo logs. Replace the MySQL binaries with the 5.7.28 binaries. Prepare the tables for upgrade. Upgrade to 8.0.18 again.

  B. Execute: mysqlcheck --check-upgrade mysql columns_priv event proc proxies_priv tables_priv.

  C. Start mysqld again using the --upgrade=FORCE option.

  D. Execute: mysqlcheck --repair mysql columns_priv event proc proxies_priv tables_priv.

  E. Go to the /mysql directory and execute: myisamchk --update-state columns_priv event proc proxies_priv tables_priv.

  Correct Answer: C

• Question 66:

  Which two statements are true about using backups of the binary log? (Choose two.)

  A. Multiple binary logs can be used to restore data.

  B. Multiple binary logs can be applied in parallel for faster data restoration.

  C. Binary logs are relatively small, and therefore, excellent for long-term storage and disaster recovery.

  D. Binary logs can always be used to unapply unwanted schema changes.

  E. They allow for point-in-time recovery of the data.

  Correct Answer: DE

• Question 67:

  All MySQL Server instances belonging to InnoDB Cluster have SSL configured and enabled.

  You must configure InnoDB Cluster to use SSL for group communication.

  Which two statements are true? (Choose two.)

  A. SSL group communication must be enabled at cluster creation time by specifying createCluster ({memberSslMode: 'REQUIRED'}).

  B. Configuring SSL group communication also configures SSL distributed recovery.

  C. An existing InnoDB Cluster must be dissolved and created from scratch to enable SSL for group communication.

  D. SSL group communication can be enabled for an existing cluster, one instance at time, by setting group_replication_ssl_mode.

  E. If only some InnoDB Cluster members are enabled for SSL group communication, and -- ssl-mode=PREFERRED, communication will fall back to unencrypted connection.

  F. SSL group communication requires the use of an additional set of parameters group_replication_recovery_*.

  Correct Answer: AF

• Question 68:

  Examine these statements, which execute successfully: TRUNCATE test; BEGIN;

  INSERT INTO test(id, name) VALUES(1, "Hello"); ROLLBACK;

  SELECT id FROM test;

  Which three storage engines would return a nonempty recordset for the test table when executing the statements? (Choose three.)

  A. NDB

  B. ARCHIVE

  C. InnopB

  D. BLACKHOLE

  E. MEMORY

  F. MyISAM

  Correct Answer: ADF

  Reference: https://dev.mysql.com/doc/refman/5.6/en/blackhole-storage-engine.html

• Question 69:

  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 all metadata, but contains no table data.

  C. It returns an error because the mysqldump command should have been used.

  D. It creates a logical backup of only the users database.

  Correct Answer: A

  the command mysqlpump --exclude-databases=% --users creates a logical backup of all MySQL user accounts as CREATE USER and GRANT statements2. The option --exclude- databases=% excludes all databases from the backup, while the option --users includes all user accounts1.

• Question 70:

  What does the binlog dump thread do?

  A. It monitors and schedules the rotation/deletion of the binary logs.

  B. It reads the relay log and executes the events contained in them.

  C. It acquires a lock on the binary log for reading each event to be sent to the slave.

  D. It connects to the master and asks it to send updates recorded in its binary logs.

  Correct Answer: D

  Reference: https://blogs.oracle.com/mysql/what-causes-replication-lag- v2#:~:text=The%20Binlog%20Dump%20Thread.,contents%20of%20its%20binary%20log.andtext=The%20slaves%20creates%20th is%20SQL,log% 20and%20apply% 20its%20contents.