Oracle 1z1-908 Exam : MySQL 8.0 Database Administrator

Which two are true about differences between logical and physical upgrades of MySQL databases? (Choose two.)

• A. Physical upgrades are much faster because they do not require restarting the mysqld process.
• B. Physical upgrades leave data in place, whereas logical upgrades require data to be restored from mysqldump-type backups taken before the upgrades.
• C. Logical upgrades are much faster because they do not require restarting the mysqld process.
• D. Post-upgrade table storage requirements after physical upgrades are usually smaller than that after logical upgrades.
• E. Physical upgrades are performed for current instances on bare metal deployments, whereas logical upgrades are used for virtual machines or containerized instances.
• F. Post-upgrade table storage requirements after logical upgrades are usually smaller than that after physical upgrades.

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. innodb_undo_directory=/dev/shm
• C. sync_binlog=0
• D. max_connections=10000
• E. buffer_pool_size=24G
• F. innodb_doublewrite=0
• G. innodb_log_file_size=1G

You are considering using file-system snapshots to back up MySQL.
Which three statements are true? (Choose three.)

• A. They do not back up views, stored procedures, or configuration files.
• B. They allow direct copying of table rows with operating system copy commands.
• C. The backup window is almost zero from the perspective of the application.
• D. They do not use additional disk space.
• E. They take roughly twice as long as logical backups.
• F. There is a slight performance cost while the snapshot is active.
• G. They work best for transaction storage engines that can perform their own recovery when restored.

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 InnoDB storage engine and statements wait while data is inserted.
• B. Your table accesses wait for the operating system level flush.
• C. You use the MyISAM storage engine for most common tables.
• D. The Innodb Buffer pool is full.

Examine this statement and output:

Which two SQL statements can jsmith execute? (Choose two.)

• A. UPDATE world.country SET Name='new' WHERE Name='old';
• B. UPDATE world.country SET Name='first' ORDER BY Name LIMIT
• C. UPDATE world.country SET Name=CONCAT('New ',Name);
• D. UPDATE world.country SET Name='one' LIMIT 1;
• E. UPDATE world.country SET Name='all';