mysqldump is a common tool for performing logical backups of MySQL databases. It generates SQL files containing CREATE and INSERT statements to rebuild the database. 1. It does not back up the original file, but converts the database structure and content into portable SQL commands; 2. It is suitable for small databases or selective recovery, and is not suitable for fast recovery of TB-level data; 3. Common options include --single-transaction, --databases, --all-databases, --routines, etc.; 4. Use mysql command to import during recovery, and can turn off foreign key checks to improve speed; 5. It is recommended to test backup regularly, use compression, and automatic adjustment.

If the second monitor is not recognized by Windows, first check whether the cable and interface are normal, try to replace the HDMI, DP or VGA cable, confirm the plug-in video output port, and test different interfaces to eliminate compatibility issues; then verify the monitor power and input source settings, and connect the monitor separately to test whether it can be recognized; then enter the Windows display settings and click the "Detection" button, or use Win P to switch the display mode, and update the graphics card driver at the same time; finally check the graphics card specifications to confirm whether it supports multi-screen output to avoid exceeding its maximum output capability.

MySQL supports transaction processing, and uses the InnoDB storage engine to ensure data consistency and integrity. 1. Transactions are a set of SQL operations, either all succeed or all fail to roll back; 2. ACID attributes include atomicity, consistency, isolation and persistence; 3. The statements that manually control transactions are STARTTRANSACTION, COMMIT and ROLLBACK; 4. The four isolation levels include read not committed, read submitted, repeatable read and serialization; 5. Use transactions correctly to avoid long-term operation, turn off automatic commits, and reasonably handle locks and exceptions. Through these mechanisms, MySQL can achieve high reliability and concurrent control.

Character set and sorting rules issues are common when cross-platform migration or multi-person development, resulting in garbled code or inconsistent query. There are three core solutions: First, check and unify the character set of database, table, and fields to utf8mb4, view through SHOWCREATEDATABASE/TABLE, and modify it with ALTER statement; second, specify the utf8mb4 character set when the client connects, and set it in connection parameters or execute SETNAMES; third, select the sorting rules reasonably, and recommend using utf8mb4_unicode_ci to ensure the accuracy of comparison and sorting, and specify or modify it through ALTER when building the library and table.

To set up asynchronous master-slave replication for MySQL, follow these steps: 1. Prepare the master server, enable binary logs and set a unique server-id, create a replication user and record the current log location; 2. Use mysqldump to back up the master library data and import it to the slave server; 3. Configure the server-id and relay-log of the slave server, use the CHANGEMASTER command to connect to the master library and start the replication thread; 4. Check for common problems, such as network, permissions, data consistency and self-increase conflicts, and monitor replication delays. Follow the steps above to ensure that the configuration is completed correctly.

To view the size of the MySQL database and table, you can query the information_schema directly or use the command line tool. 1. Check the entire database size: Execute the SQL statement SELECTtable_schemaAS'Database',SUM(data_length index_length)/1024/1024AS'Size(MB)'FROMinformation_schema.tablesGROUPBYtable_schema; you can get the total size of all databases, or add WHERE conditions to limit the specific database; 2. Check the single table size: use SELECTta

When you encounter the "DefaultGatewayisNotAvailable" prompt, it means that the computer cannot connect to the router or does not obtain the network address correctly. 1. First, restart the router and computer, wait for the router to fully start before trying to connect; 2. Check whether the IP address is set to automatically obtain, enter the network attribute to ensure that "Automatically obtain IP address" and "Automatically obtain DNS server address" are selected; 3. Run ipconfig/release and ipconfig/renew through the command prompt to release and re-acquire the IP address, and execute the netsh command to reset the network components if necessary; 4. Check the wireless network card driver, update or reinstall the driver to ensure that it works normally.

When encountering the "SYSTEM_SERVICE_EXCEPTION" blue screen error, you do not need to reinstall the system or replace the hardware immediately. You can follow the following steps to check: 1. Update or roll back hardware drivers such as graphics cards, especially recently updated drivers; 2. Uninstall third-party antivirus software or system tools, and use WindowsDefender or well-known brand products to replace them; 3. Run sfc/scannow and DISM commands as administrator to repair system files; 4. Check memory problems, restore the default frequency and re-plug and unplug the memory stick, and use Windows memory diagnostic tools to detect. In most cases, the driver and software problems can be solved first.