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- Understanding MySQL binlog formats (STATEMENT, ROW, MIXED)
- MySQL binlog has three formats: STATEMENT, ROW and MIXED. STATEMENT records SQL statements with the advantage of small logs and strong readability, but may lead to inconsistency between master and slaves; ROW records specific changes in each line to ensure consistency, but the logs are large and poor readability; MIXED automatically switches both, taking into account performance and accuracy, but there is still a potential risk of replication exceptions. The binlog format can be viewed and set through commands or configuration files. When selecting, consistency and performance should be weighed according to business needs.
- Mysql Tutorial . Database 756 2025-07-02 16:15:11
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- Analyzing MySQL EXPLAIN plan output for query tuning
- To understand how MySQL executes queries, first use the EXPLAIN tool to analyze the query plan. 1. Priority is given to view the type column, and its value reflects the access efficiency of the table. For example, system/const is the best and ALL is the worst, so it should be avoided as much as possible; 2. Pay attention to the prompts in the Extra column, such as Usingfilesort and Usingtemporary represent sorting or temporary table problems, and the index or query structure needs to be optimized; 3. Combine rows and filtered columns to evaluate query efficiency. If rows are large and filtered small, it means that the filtering efficiency is low, and the index or condition order needs to be improved; 4. Optimize query performance by creating composite indexes, splitting complex queries, and using more accurate conditions in advance.
- Mysql Tutorial . Database 627 2025-07-02 16:14:11
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- Understanding InnoDB transaction isolation levels in MySQL
- InnoDB's transaction isolation level balances consistency and performance by controlling transaction concurrency behavior. 1. The isolation level determines the degree of visible data modification between transactions, preventing dirty reading, non-repeatable reading and phantom reading problems; 2. The four levels are ReadUncommitted (almost not used), ReadCommitted (performance priority), RepeatableRead (default level) and Serializable (high consistency requirements), each preventing different types of concurrency problems; 3. The isolation level at the global or session level can be set through the SET command, and it is recommended to configure it explicitly in the connection pool or ORM; 4. Notes include: the default RR is not necessarily suitable for all scenarios, and the pro-key under RR
- Mysql Tutorial . Database 486 2025-07-02 16:09:50
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- Implementing SSL/TLS encryption for MySQL connections
- The MySQL connection enables SSL/TLS encryption to prevent data from being eavesdropped or tampered during transmission and ensures the security of communication between the client and the server. 1. First, confirm whether the MySQL version supports SSL, and check it through the SHOWVARIABLESLIKE'have_ssl' command. If you return NO, you need to install the OpenSSL component or use a distribution version that supports SSL; 2. Prepare the CA certificate, server certificate and private key files, you can build your own CA and generate related files. The test environment can use a self-signed certificate. It is recommended to use a trusted CA to issue it in the production environment; 3. Specify the ssl-ca, ssl-cert and ssl-key paths in the MySQL configuration file, and restart MySQL
- Mysql Tutorial . Database 279 2025-07-02 16:02:21
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- Implementing partitioning in large MySQL tables
- PartitioningimprovesMySQLperformanceforlargetablesbysplittingthemintosmallerparts.Itworksbestfortime-baseddatawithsubsetqueries,maintenance-heavyoperations,orwhenavoidingapplicationchanges.UseRANGEpartitioningfordate-baseddata,HASH/KEYforevendistribu
- Mysql Tutorial . Database 561 2025-07-02 15:54:20
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- Optimizing MySQL query performance with indexes
- The core reason why indexing can improve the speed of MySQL query is that it avoids full table scanning through a directory structure, thereby quickly locates data pages. 1. Indexes reduce data scanning like directories, especially for WHERE, JOIN, and ORDERBY operations; 2. Not all scenarios are applicable. Too many indexes will take up space, reduce write speed, and may mislead the optimizer; 3. Determine whether you need to add an index, you can view the type (ref/range/const as hit), key (displaying index) and rows in the execution plan through the EXPLAIN command; 4. Scenarios that often need to add an index include WHERE conditional column, JOIN connection column, ORDERBY and GROUP
- Mysql Tutorial . Database 637 2025-07-02 15:35:31
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- Handling large BLOB/TEXT data efficiently in MySQL
- MySQL is prone to encounter performance bottlenecks when processing large-capacity BLOB and TEXT data, and requires a variety of optimization strategies. 1. Avoid frequent query of large fields, only specify field name query when needed or split large fields into separate tables and associate with foreign keys. 2. Choose the appropriate field type according to actual needs, such as TINYTEXT, MEDIUMTEXT or VARCHAR, and avoid blindly using the maximum capacity type. 3. Pay attention to the performance impact of temporary tables and sorting, avoid sorting or grouping large fields, use overwrite index or summary fields instead, and adjust memory parameters appropriately. 4. Use compression and external storage appropriately, enable InnoDB line compression to save space or store large files in the file system, and the database only saves paths.
- Mysql Tutorial . Database 828 2025-07-02 15:30:50
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- Using stored procedures and functions in MySQL
- The main difference between stored procedures and functions is their purpose and call method. 1. A stored procedure can have multiple input and output parameters, which are called using CALL, which is suitable for performing complex operations and returning multiple result sets; 2. The function must return a value, and the parameters can only be input types, which are usually used for calculations in a query. To create stored procedures, you need to use the DELIMITER separator, which contains input, output parameters and process body logic, such as obtaining a name through the user ID; while to create a function, you need to specify the return type, and there cannot be output parameters, such as determining whether the user exists. When using it, you need to pay attention to issues such as permissions, debugging difficulties, version compatibility and performance optimization. Rational use can improve code reuse rate and system maintainability.
- Mysql Tutorial . Database 865 2025-07-02 15:30:21
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- Using Common Table Expressions (CTEs) in complex MySQL queries
- CTE (CommonTableExpression) is a temporary result set used to simplify complex MySQL queries. It is defined by a WITH clause and exists only during the execution of a single query. It is often used to improve readability, handle recursive queries, and reuse logic. 1. The basic structure of CTE is: WITHcte_nameAS (query definition), followed by the main query; 2. Suitable for multi-layer nesting, duplicate subqueries or scenes requiring modular logic; 3. Support recursive queries, suitable for processing hierarchical data, such as organizational structure, whose structure contains basic query and recursive parts, and uses UNIONALL connection; 4. Pay attention to avoid infinite loops and is limited by the depth of recursive MySQL; 5. Although it is not as good as index optimization JOI
- Mysql Tutorial . Database 686 2025-07-02 15:27:31
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- Troubleshooting MySQL error 1045 (Access denied)
- MySQL error 1045 (Accessdenied) is usually caused by incorrect username, password, or improper permission settings. 1. First, confirm whether the entered username and password are correct, pay attention to case sensitivity, and check whether there are any spelling errors in the configuration file; 2. Make sure that the user permission allows remote or local connections, you can view it through SELECTUser and HostFROMmysql.user, and create a new user that allows remote connections and authorize it if necessary; 3. Check the bind-address settings in the MySQL configuration file to ensure that its binding address is consistent with the access requirements, such as 0.0.0.0 allows external connections; 4. Troubleshoot other factors, including operating system user authentication methods and MySQL services
- Mysql Tutorial . Database 236 2025-07-02 15:25:20
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- Comparing InnoDB and MyISAM storage engines in MySQL
- InnoDB should be used in scenarios that require transaction support, row-level locks, data integrity and foreign key constraints. MyISAM is suitable for read-intensive and transaction-free scenarios. 1. If ACID compliance and transaction processing are required, such as banking systems, InnoDB should be selected; 2. If concurrent write operations are frequent, InnoDB's row-level lock is better than MyISAM's table-level lock; 3. If reading is mainly used and the data is static, MyISAM has better performance, but if there are many write operations, InnoDB should be selected; 4. If foreign keys or modern full-text search functions are required, InnoDB is the first choice, although MyISAM still has advantages in certain specific full-text search scenarios.
- Mysql Tutorial . Database 494 2025-07-02 15:22:31
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- Troubleshooting common MySQL errors and solutions
- Common MySQL errors include connection failure, SQL syntax error, startup failure, etc. When you cannot connect, first confirm whether MySQL is running, whether the port is open, whether the access permissions are correct, and whether the bind-address configuration is reasonable; SQL error 1064 or 1054 requires checking whether the syntax and field exist, and use tools to assist in verification; if the startup fails, you should check the error log, check the data directory permissions, handle the PID file remaining or InnoDB corruption; other problems such as foreign key constraint failure, full table, and excessive connections exceeding the limit also need to be dealt with in a targeted manner.
- Mysql Tutorial . Database 673 2025-07-02 15:20:51
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- Troubleshooting MySQL high CPU usage issues
- MySQL's CPU occupancy is usually caused by slow queries, improper configuration or resource competition. It is necessary to check from the following aspects: 1. Check whether there are slow queries being executed, and use SHOWPROCESSLIST and slow queries log location time-consuming SQL; 2. Analyze and optimize the database structure and index to ensure that frequent query fields have index support to avoid index failure caused by function operations; 3. Check whether MySQL configuration is reasonable, such as innodb_buffer_pool_size, max_connections and other parameters, and evaluate with tools such as mysqltuner.pl; 4. Monitor system resources and load conditions, and exclude CPU usage by other services or timing tasks.
- Mysql Tutorial . Database 191 2025-07-02 15:17:01
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- Using and interpreting MySQL Performance Schema
- MySQL's PerformanceSchema is a built-in database engine for monitoring MySQL's internal runtime performance information. The enable method is as follows: 1. The default majority of versions are enabled, and you can check the status by SHOWVARIABLESLIKE' performance_schema'; 2. If OFF, add performance_schema=ON in the [mysqld] part of my.cnf or my.ini, and restart takes effect; 3. Note that the old version may need to be compiled and enabled manually. Common monitoring tables include: 1. events_statements_summary_by_digest is used to locate the most expensive
- Mysql Tutorial . Database 632 2025-07-02 15:04:22
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