What is the mysql version query command?

Finding large tables in MySQL can be achieved by querying system tables or checking physical files. 1. Use the information_schema.TABLES table to execute SQL statements to filter out tables with large data volume and large space, and sort them by size; 2. Enter the MySQL data directory through server access permissions, use the command to view the .ibd file size to locate the large table; 3. Analyze the real "large" table based on the index and fragmentation situation, use the DATA_FREE field to view the fragmented space, and execute OPTIMIZETABLE if necessary for optimization. The above methods help identify and deal with large table problems that affect performance from three aspects: statistical information, physical files and storage efficiency.

When dealing with large objects (BLOB/TEXT) in MySQL, you need to pay attention to performance and design. 1. Select BLOB or TEXT according to the data type. TEXT is suitable for text, BLOB is used for binary content, and pay attention to the influence of character sets. 2. Avoid using large object types in frequent query fields. It is recommended to split them into separate tables and associate them through foreign keys. 3. Use indexes reasonably, such as prefix indexes or FULLTEXT indexes, to avoid blindly adding normal indexes. 4. Prioritize the use of the InnoDB storage engine and optimize the configuration, such as turning on innodb_file_per_table and considering partitioning strategies to improve the processing efficiency of large objects.

MySQLProxy is a lightweight database middleware for load balancing and failover. Its core functions include: 1. Query analysis and rewrite; 2. Load balancing; 3. Failover. Configuring load balancing requires controlling traffic through Lua scripts, such as polling SELECT requests to multiple slave libraries. Failover requires the script to listen to the connection status, mark the failed node and temporarily skip it. Note when using: 1. The single-threaded model may affect high concurrency performance; 2. Lua script development requires certain capabilities; 3. Lack of built-in health checks; 4. Limited support for connection pools. Overall, it is suitable for scenarios with limited resources and simple needs.

The security configuration of MySQL database in a hybrid cloud environment needs to focus on the following four aspects: 1. Network access control is the first line of defense, and the database exposure range should be restricted through firewall rules, binding designated network interfaces, and using VPC peer-to-peer connections; 2. Enable and correctly configure SSL encrypted connections to ensure data transmission security and prevent man-in-the-middle attacks; 3. User permissions and authentication strategies should be refined, follow the principle of minimum permissions, create a dedicated account and restrict source; 4. Regular audits and log monitoring, use the log analysis platform to promptly detect abnormal behaviors, improve overall security.

AsolidMySQLdisasterrecoveryplanrequiresunderstandingpriorities,choosingtherightbackupstrategy,settingupreplication,andpracticingrecovery.1.IdentifycriticaldatabasesanddefineRPO/RTOtodeterminebackupfrequency.2.Choosebetweenfullorincrementalbackupsusin

PerconaToolkit can realize MySQL monitoring through four core tools: 1. Use pt-query-digest to analyze slow query logs and locate time-consuming SQL; 2. Use pt-heartbeat to monitor master-slave replication delays and detect delay times; 3. Check configuration risks through pt-variable-advisor to obtain optimization suggestions; 4. Use pt-online-schema-change to observe performance impacts when structural changes. These tools are lightweight and efficient, suitable for quickly diagnosing and monitoring MySQL running status.

When designing an inventory management database, you need to clarify the core table structure, handle inventory changes, optimize query and report, and consider scalability. 1. The core table includes products, warehouses, inventory, and in-store records. Each table has clear fields and ensures consistency through foreign key associations. 2. Inventory changes are processed through transaction updates. Inventory operations are first written to Transactions and then updated to Inventory. Transactions are used to avoid concurrency problems and negative value checks are performed. 3. Query optimization includes establishing composite indexes in the Transactions table, using views to simplify logic, and generating summary tables to accelerate reports. 4. Extended

TotrackchangesinaMySQLdatabase,usehistorytableswithtriggersorapplication-levellogging.1.Createashadowtableforeachtrackedtablewithextrafieldslikerevision\_id,revision\_type,revision\_timestamp,andrevision\_user.2.Usetriggerstoautomaticallylogchangesbe