Oracle Oracle Certifications 1Z0-908 Questions & Answers

• Question 31:

  The data in this instance is transient; no backup or replication will be required. It is currently under performing.

  The database size is static and including indexes is 19G.

  Total system memory is 32G.

  After profiling the system, you highlight these MySQL status and global variables:

  

  The OS metrics indicate that disk is a bottleneck. Other variables retain their default values.

  Which three changes will provide the most benefit to the instance? (Choose three.)

  A. innodb_flush_log_at_trx_commit=1

  B. buffer_pool_size=24G

  C. innodb_log_file_size=1G

  D. sync_binlog=0

  E. innodb_doublewrite=0

  F. max_connections=10000

  G. innodb_undo_directory=/dev/shm

  Correct Answer: ACF

  Reference: https://aws.amazon.com/blogs/database/best-practices-for-configuring- parameters-for-amazon- rds-for-mysql-part-1-parameters-related-to-performance/

• Question 32:

  You are using mysqlcheck for server maintenance. Which two statements are true? (Choose two.)

  A. The mysqlcheck --check --all-databases command takes table write locks while performing a series of checks.

  B. The mysqlcheck --optimize --all-databases command reclaims free space from table files.

  C. The mysqlcheck --repair --all-databases command can repair an InnoDB corrupted table.

  D. The mysqlcheck command can be renamed mysqlrepair so that it repairs tables by default.

  E. The mysqlcheck --analyze --all-databases command performs a series of checks to spot eventual table corruptions.

  Correct Answer: DE

• Question 33:

  You plan to take daily full backups, which include the ndbinfo and sys (internal) databases. Which command will back up the databases in parallel?

  A. mysqldump --single-transaction > full-backup-$(date +%Y%m%d).sql

  B. mysqlpump --include-databases=% > full-backup-$(date +%Y%m$d).sql

  C. mysqlpump --all-databases > full-backup-$(date +%Y%m%d).sql

  D. mysqldump --all-databases > full_backup-$(date +%Y%m%d).sql

  Correct Answer: B

  https://dev.mysql.com/doc/refman/8.0/en/mysqlpump.html By default --all-databases won't backup ndbinfo schema this can be done via --include- database=%https://dev.mysql.com/doc/refman/8.0/en/mysqlpump.html#mysqlpumprestrictions

• Question 34:

  Examine this snippet from the binary log file named binlog.000036:

  

  The rental table was accidentally dropped, and you must recover the table. You have restored the last backup, which corresponds to the start of the binlog.000036 binary log. Which command will complete the recovery?

  A. mysqlbinlog --stop-position=500324 binlog.000036 | mysql

  B. mysqlbinlog --stop-datetime='2019-ll-20 14:55:18' binlog.000036 | mysql

  C. mysqlbinlog --stop-position=5004S3 binlog.000036 | mysql

  D. mysqlbinlog --stop-datetime='2019-ll-20 14:55:16' binlog.000036 | mysql

  Correct Answer: D

• Question 35:

  Which two statements are true about using MySQL Enterprise Monitor Query Analyzer? (Choose two.)

  A. The single query QRTi pie chart in the Query Analyzer view is based on the average execution of all statements.

  B. It is possible to retrieve a normalized statement, but never the exact statement that was executed.

  C. It is possible to configure the Query Analysis built-in advisor to get notified about slow query execution.

  D. It is possible to list and analyze statements in an arbitrary graph range selection from timeseries graphs.

  E. It is possible to import data into the Query Analyzer from heterogeneous sources, such as CSV.

  Correct Answer: CD

• Question 36:

  There are five MySQL instances configured with a working group replication. Examine the output of the group members:

  

  Which two statements are true about network partitioning in the cluster? (Choose two.)

  A. The cluster will shut down to preserve data consistency.

  B. The cluster has built-in high availability and updates group_replication_ip_whitelist to remove the unreachable nodes.

  C. The group replication will buffer the transactions on the online nodes until the unreachable nodes return online.

  D. There could be both a 2 node and 3 node group replication still running, so shutting down group replication and diagnosing the issue is recommended.

  E. A manual intervention to force group members to be only the working two instances is required.

  Correct Answer: AB

• Question 37:

  A clean shutdown was performed with innodb_fast_shutdown=0.

  While you were manipulating files, all files were accidentally deleted from the top-level data directory.

  Which two files must be restored from backup to allow the DB to restart cleanly? (Choose two.)

  A. ibtmp1

  B. undo_001

  C. ib_buffer_pool

  D. ibdata1

  E. mysql.ibd

  F. ib_logfile0

  Correct Answer: CE

• Question 38:

  You must run multiple instances of MySQL Server on a single host. Which three methods are supported? (Choose three.)

  A. Run MySQL Server docker containers.

  B. Use systemd with different settings for each instance.

  C. Use system tools to lock each instance to its own CPU.

  D. Start mysqld or mysqld_safe using different option files for each instance.

  E. Run mysqld with --datadir defined for each instance.

  F. Use resource groups to lock different instances on separate CPUs.

  Correct Answer: BDE

• Question 39:

  A colleague complains about slow response time on your website. Examine this query and output:

  

  What is the most likely cause for the high number of lock waits?

  A. You use the MyISAM storage engine for most common tables.

  B. You use the InnoDB storage engine and statements wait while data is inserted.

  C. The Innodb Buffer pool is full.

  D. Your table accesses wait for the operating system level flush.

  Correct Answer: B

  Reference: https://severalnines.com/database-blog/how-fix-lock-wait-timeout-exceeded- error-mysql

• Question 40:

  You encountered an insufficient privilege error in the middle of a long transaction.

  The database administrator is informed and immediately grants the required privilege:

  GRANT UPDATE ON world.city TO `user1';

  How can you proceed with your transaction with the least interruption?

  A. Roll back the transaction and start the transaction again in the same session.

  B. Re-execute the failed statement in your transaction.

  C. Change the default database and re-execute the failed statement in your transaction.

  D. Close the connection, reconnect, and start the transaction again.

  Correct Answer: B