Using stored procedures and escaping user input helps mitigate SQL injection by ensuring user input is treated as data rather than executable code. The other methods are less effective in protecting dynamic SQL.

The –exclude-tables-list option in mysqlpump allows excluding specific tables from the logical backup. –skip-backup-mode is not valid. –disable-storage-lock does not exclude tables, and –ignore-dump-errors allows skipping errors, not specific tables.

To enable semi-synchronous replication, the primary must wait for at least one replica to acknowledge a transaction before committing, requiring both rpl_semi_sync_master and rpl_semi_sync_slave settings.

The ANALYZE TABLE command updates index statistics, allowing the optimizer to make better execution decisions. FLUSH TABLES clears table cache but does not recalculate statistics. CHECK TABLES verifies table integrity, and RESET MASTER resets binary logs, which is unrelated to indexing.

The correct command to revoke all privileges and grant options from a user is REVOKE ALL PRIVILEGES, GRANT OPTION FROM ‘user‘@‘host‘. REVOKE ALL ON . FROM is incorrect syntax, DELETE FROM mysql.db is not the proper way to manage privileges, and REMOVE PRIVILEGES does not exist in MySQL.

The performance_schema.threads table provides information on active threads, including query execution state and resource usage. Other tables focus on events, statistics, or query execution history.

The mysql.index_stats table contains detailed statistics on indexed columns. SHOW INDEXES FROM provides index metadata but lacks performance details. SHOW INDEX STATUS FROM is invalid. EXPLAIN ANALYZE FORMAT gives execution plans but not index-specific statistics.

The replicate_do_db parameter enables database-level filtering per replication channel, making it crucial for multisource replication. The log_slave_updates option tracks applied transactions, but it does not filter replication. The other options relate to network timeouts and transaction durability.

The MySQL Shell function dba.createCluster() is used to initialize an InnoDB Cluster. INSTALL COMPONENT, group_replication_mode, and CHANGE MASTER TO are not required for cluster initialization.

In semi-synchronous replication, the I/O thread ensures that the primary server waits for at least one acknowledgment from a replica before committing a transaction. The SQL thread applies transactions, and Worker threads execute queries but do not manage acknowledgments.

Using SSL/TLS encryption ensures that data between MySQL and the host is securely transmitted, preventing unauthorized access. The other options are beneficial, but SSL/TLS encryption directly secures communication.

Binary log backups capture all changes at the transaction level, making them ideal for high-transaction databases. Logical dump exports are slow for large datasets. Periodic full backups take longer and use more storage, while Snapshot image copies may lack real-time transaction consistency.

The default location for the MySQL global option file is /etc/mysql/my.cnf on Unix-based systems. The other paths are not typically used for default configurations.

The FAILED_LOGIN_ATTEMPTS setting allows MySQL to lock user accounts after a defined number of failed logins, preventing brute-force attacks. The other options are not valid MySQL settings.

Semi-synchronous replication improves availability by ensuring at least one replica receives a transaction before the primary commits, reducing data loss risks but not fully enforcing synchronous consistency.

By default, MySQL stores error logs in /var/log/mysql_error_log/ on Linux systems. The other options do not correspond to valid MySQL error log directories.

The Query Explorer in MySQL Enterprise Monitor enables graphical query performance analysis, allowing users to sort, filter, and compare queries based on various execution metrics. The Dashboard and Replication Monitor provide different types of monitoring.

The FILTERED mode in MySQL Enterprise Audit logs only explicitly defined events, improving performance and reducing log size. The FULL mode captures all activities, and MIXED mode applies both filtering and global rules.

Hot backup mode in MySQL Enterprise Backup allows taking a backup while the database is running without locking tables. Full copy backup does not specify whether it locks tables. Logical dump export uses mysqldump, and Compressed archive refers to backup storage format, not locking behavior.

To start MySQL using systemd, use systemctl restart mysqld or systemctl start mysqld. The other options do not correspond to valid systemd commands for MySQL.

Raw file backups must include ibdata1, ib_logfile0, and ib_logfile1, which store InnoDB data and redo logs. Log files are not necessary for restoring data. Configuration files can be recreated, and temporary files are not persistent.

The binary log is a key component in MySQL replication, recording all modifying transactions (INSERT, UPDATE, DELETE) on the primary server. Replicas use this log to apply changes in the same order, ensuring data consistency. It does not store schema metadata or user privileges, which are managed separately. It is also not intended for performance tuning, as that is handled by tools like the Performance Schema and slow query log.

Enabling local_infile=ON allows users to load data from local files, which can lead to file inclusion vulnerabilities. log_bin supports replication and auditing. require_secure_transport ensures encrypted connections. validate_password_policy=STRONG enforces strong passwords, improving security.

To disable MySQL auto-start on boot, use systemctl disable mysqlserver. The other options reference incorrect service names and are not valid systemd commands.

The socket option is configured in the [client] section of the option file for client-server communication. It does not use mysql.socket, network files, or environment variables.

The correct syntax for creating a user with mysql_native_password is CREATE USER ‘user‘@‘host‘ IDENTIFIED WITH plugin BY ‘password‘. Using IDENTIFIED USING is incorrect syntax, and IDENTIFIED WITH plugin alone does not specify a password. The default authentication plug-in in MySQL 8.0 is caching_sha2_password, so explicitly specifying mysql_native_password is necessary.

Setting super_read_only_mode to ON prevents updates to the Data Dictionary. The other options are incorrect or do not exist in MySQL 8.0.

The InnoDB Transaction Logs ensure data consistency by using redo logs and undo logs to support ACID transactions. MyISAM does not support transactions, Query Cache only caches results, and MEMORY tables do not provide durability across restarts.

The force index hint explicitly instructs MySQL to use a specified index, even if the optimizer determines another method would be more efficient. It does not create indexes or manage query caching.

The InnoDB Storage Engine is the best choice for large-scale databases due to its transactional support, crash recovery, and row-level locking. The Memory Engine is volatile, CSV is inefficient for large datasets, and Archive lacks indexing.

The InnoDB Buffer Pool caches frequently accessed indexes and data pages in memory, significantly reducing disk I/O and improving performance. Query Cache was removed in MySQL 8.0 due to inefficiencies in multi-core environments. Performance Schema is used for monitoring but does not cache data. MySQL Query Optimizer helps in query execution planning but does not store data in memory for reuse.

Each Group Replication node requires group_replication_local_address to define its network address for inter-node communication. Auto failover and binlog format options do not exist, and start_on_boot is optional but not required.

Multisource replication does not support updates to the same table from multiple sources, as this can cause conflicting writes. GTIDs are supported, commit acknowledgments apply to semi-synchronous mode, and there is no minimum number of required primary servers.

The Replication Dashboard provides real-time metrics on replication health, including lag, slave status, and binlog processing rates. Other tools do not specifically focus on replication issues.

MySQL automatically creates an index for foreign keys, but not a composite index unless explicitly specified. A clustered index is inherently created for PRIMARY KEYs in InnoDB. A secondary index is created when an index is added on a non-primary column. A non-unique index is often used for foreign keys, but composite indexing must be manually defined.

The datadir_location_path variable defines the directory where MySQL stores its databases. The other options are not valid MySQL configuration variables.

The sp_set_firewall_mode stored procedure is used to configure MySQL Enterprise Firewall for a user, with modes such as OFF, DETECTING, and ENFORCE. The other options are invalid MySQL commands.

MySQL’s InnoDB storage engine supports row-level locking, which allows multiple transactions to access different rows of a table simultaneously. This improves concurrency and performance compared to table-level locking, where an entire table is locked even if only a single row is updated. The “Read uncommitted“ isolation level does not guarantee data consistency since it allows reading uncommitted changes. A full-table scan refers to a query execution method rather than a concurrency control feature.

When a quorum is lost, the cluster cannot safely apply transactions, so all writes stop. It does not switch to read-only mode, auto-sync transactions, or elect a leader without a majority quorum.

The –slave-info recovery option ensures that backups contain replication metadata, making it easier to restore replication consistency. –binlog-expire backup controls binary log expiration. –buffer-pool dump saves InnoDB memory pages, and –query-log archive stores general logs, not replication info.

When log_output is set to TABLE, logs are written to MySQL’s system tables instead of files. The FILE setting logs to disk, while BOTH enables both storage methods.

To enable GTID-based replication, MySQL requires enforce-gtid-consistency to ensure transaction consistency and gtid-mode to track transactions across servers without relying on binary log positions.

The Performance Schema provides detailed insights into query execution, resource consumption, and wait events. It is specifically designed for performance monitoring and troubleshooting, making it the best tool for analyzing high-resource-consuming queries. The SHOW PROCESSLIST command provides real-time information about currently running queries but does not offer historical performance data. The mysqlbinlog tool is used for inspecting binary logs, primarily for replication and point-in-time recovery purposes. The general query log records all executed queries but lacks performance-related details.

The SUPER privilege allows users to configure the MySQL server and make system-level changes. It is important to limit this privilege to trusted users, as it provides full administrative control. The other options do not exist in MySQL 8.0.

The innodb_buffer_pool_instances variable divides the buffer pool into multiple instances, reducing contention in multi-threaded environments. The other options control I/O capacity, log buffer size, and flushing behavior.

The transaction_isolation variable sets the default isolation level for transactions, with options like READ COMMITTED, REPEATABLE READ, and SERIALIZABLE. innodb_autocommit affects transaction commits, transaction_mode is not a valid variable, and transaction_read_only controls whether transactions can modify data but does not set isolation levels.

Partitioning helps manage large datasets efficiently by splitting tables based on defined criteria, improving query performance and scalability. Query caching is deprecated, replication aids performance but does not manage size, and buffer pool expansion only affects memory use.

A logical export allows restoring to a previous MySQL version. Binary log flashback, restarting services, or forced downgrades do not guarantee safe rollback.

The correct way to remove all privileges from a user without deleting the account is REVOKE ALL PRIVILEGES, GRANT OPTION FROM user. DROP USER removes the user entirely, REVOKE ALL ON . FROM is incorrect syntax, and manually deleting from mysql.user is not a recommended approach.

MySQL Enterprise Monitor detects queries that perform full table scans, indicating missing or ineffective indexes. It does not automatically create indexes or monitor fragmentation levels.

Using SSL certificate-based authentication ensures that both the client and server encrypt all communication, preventing unauthorized interception. The other options focus on password security but do not guarantee encryption of the connection.

In MySQL 8.0, roles are granted to users using GRANT ‘role‘ TO ‘user‘@‘host‘. ASSIGN ROLE, SET ROLE, and ADD ROLE are invalid MySQL commands. Roles must be explicitly granted before they can be used.

The Performance Schema is an advanced monitoring tool in MySQL that provides real-time insights into server performance, including query execution, memory usage, and wait events. It has minimal impact on query performance, unlike traditional logging mechanisms. Unlike the slow query log, which only tracks slow queries, the Performance Schema offers comprehensive monitoring capabilities. It does not replace binary logging, which is used for replication and recovery.

The MySQL Enterprise Agent is responsible for collecting monitoring data from MySQL servers and transmitting it to the Enterprise Monitor. The Performance Schema is a built-in MySQL feature, the Event Scheduler is unrelated, and the Query Analyzer focuses only on query performance.

InnoDB Undo Tablespace Files store undo logs, which track transaction rollbacks and MVCC snapshots. The redo log files (ib_logfile*) ensure durability, the doublewrite buffer prevents corruption, and the shared tablespace stores user data.

The –zlib-compression-mode option enables compression in mysqlpump, reducing backup file size for large databases. –gzip-backup-option is incorrect. –deflate-store-enable does not exist, and –compressed-file-output is an invalid option.

The Last_SQL_Errno field stores the most recent SQL thread error code, helping diagnose failed transactions. It does not track last transaction status, network failures, or binary log positions, which are handled by other replication status fields.

Before purging binary logs, all replicas must be fully synchronized to prevent replication failure. Restarting MySQL, flushing logs, and log_bin_trust_function settings do not ensure replication safety.

A Shared Lock allows other transactions to read but prevents them from modifying the locked rows. Exclusive Locks block all access, Intention Locks only indicate intent, and Auto-commit Locks do not exist.

Single-primary mode ensures only one node accepts writes, preventing conflicts. Asynchronous replication, disabling logs, or increasing timeouts do not ensure safe transactions.