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  • Configuring the InnoDB buffer pool size for MySQL performance
    Configuring the InnoDB buffer pool size for MySQL performance
    Setting the InnoDB buffer pool size should be reasonably configured according to the purpose of the server and memory resources. 1. The server dedicated to MySQL can be set to 50%~80% of the physical memory; 2. Small applications 1GB~4GB, several GB to tens of GB in medium environments, and hundreds of GB in large high-concurrency systems; 3. Use SHOWENGINEINNODBSTATUS or specific SQL query buffer pool usage; 4. Modify the configuration and set innodb_buffer_pool_size in my.cnf or my.ini and restart MySQL; 5. Pay attention to shared memory, warm-up problems and version differences in multiple instances. MySQL8.0 supports dynamic adjustment. Properly configure buffer pool energy
    Mysql Tutorial . Database 184 2025-07-08 02:38:01
  • Implementing Referential Integrity with MySQL Foreign Keys
    Implementing Referential Integrity with MySQL Foreign Keys
    Foreign key constraints ensure data consistency by associating inter-table fields. In MySQL, a foreign key is a field that references another table's primary or unique key, such as orders.user_id references users.id, to prevent orders with invalid user ID from being inserted. Supports cascading operations, including RESTRICT blocking deletion, CASCADE automatically deletes associated records, and SETNULL is set to empty (when NULL is allowed). Note when using: Only the InnoDB engine supports foreign keys, and ENGINE=InnoDB is required; the foreign key field will automatically create an index, but it is recommended to manually establish it to avoid performance differences; the field type, character set and sorting rules must be consistent; foreign keys affect transaction execution, and lock problems may be caused under high concurrency. final,
    Mysql Tutorial . Database 563 2025-07-08 02:36:21
  • Writing stored procedures and functions in MySQL
    Writing stored procedures and functions in MySQL
    The difference between stored procedures and functions is their purpose and call method: 1. Stored procedures can have multiple input and output parameters or no parameters, and are called using CALL; the function must have a return value and can only have one RETURNS value, which can be called in SELECT. 2. Before writing the storage structure, you need to use DELIMITER to replace the ending character such as // or $$ to avoid parsing the semicolon in advance, and restore the default separator after writing. 3. Variable declarations should be placed before all statements, use DECLARE to define local variables, and pay attention to the correct format of process control syntax such as IF, CASE, LOOP, and WHILE. 4. Debugging can be inserted into debug information by log table. It is recommended to add comments to explain the functions and parameters meanings, keep the logic clear, clean redundant objects regularly, and provide
    Mysql Tutorial . Database 134 2025-07-08 02:34:41
  • Using subqueries and derived tables effectively in MySQL
    Using subqueries and derived tables effectively in MySQL
    Using subqueries and derived tables can improve the expression capabilities of MySQL query, but attention should be paid to performance and readability. 1. Use subqueries when filtering or computing based on dynamic data to avoid excessive nesting or related subqueries; 2. Derived tables are used to simplify complex joins or pre-aggregated data, and alias must always be specified; 3. Prioritize indexes, execution plans and rewrite them to JOIN or CTE if necessary; 4. Keep the SQL format clear and use meaningful alias to improve maintainability.
    Mysql Tutorial . Database 752 2025-07-08 02:20:40
  • Identifying Typical Performance Issues in MySQL
    Identifying Typical Performance Issues in MySQL
    The query does not use the index, which will lead to full table scanning, and the execution plan should be analyzed and optimized through EXPLAIN; 2. The database configuration is unreasonable, such as the buffer pool is too small, which will affect performance, and parameters such as innodb\_buffer\_pool\_size should be adjusted; 3. The table structure design is not standardized, such as wrong field type or redundancy, which will lead to inefficient query. The design should be standardized and the field type should be selected reasonably. MySQL performance problems are common in improper index usage, unreasonable configuration and poor table structure design. During the investigation, you should give priority to checking slow query logs, execution plans and index usage, and then combine configuration tuning and table structure adjustment to improve performance.
    Mysql Tutorial . Database 954 2025-07-08 02:02:41
  • Preventing SQL injection vulnerabilities in MySQL applications
    Preventing SQL injection vulnerabilities in MySQL applications
    There are three key measures to prevent SQL injection: 1. Use parameterized queries, such as PDO of PHP or Python's cursor.execute() combined with parameter tuples, to ensure that user input is always processed as data rather than SQL code; 2. Verify and filter the input, use the whitelist mechanism to check the format and limit the length, and avoid relying on blacklists; 3. Avoid exposing database error information. The production environment should block detailed error reports and return fuzzy error prompts to prevent attackers from exploiting them.
    Mysql Tutorial . Database 400 2025-07-08 01:53:30
  • Analyzing and reducing disk space usage in MySQL
    Analyzing and reducing disk space usage in MySQL
    To reduce MySQL disk usage, first find out the table that takes up the most space by querying information_schema; secondly, clean up unnecessary historical data and delete or archive it in batches; then optimize the table structure and index, such as deleting redundant indexes, adjusting field types, splitting large field tables, and performing OPTIMIZETABLE to recycle free space; finally, consider enabling InnoDB table compression or using partitioned tables to further save storage space.
    Mysql Tutorial . Database 176 2025-07-08 01:45:40
  • Troubleshooting slow query execution times in MySQL
    Troubleshooting slow query execution times in MySQL
    Solutions to slow execution of MySQL query include optimizing SQL statements, using indexes reasonably, adjusting configuration parameters, and other detailed optimizations. 1. Optimize SQL: Avoid SELECT*, use LIMIT to reduce the amount of data, simplify JOIN, and do not operate field functions in WHERE; 2. Use index: Create indexes for commonly used query fields, pay attention to combining index order, avoid excessive indexes and analyze tables regularly; 3. Adjust configuration: Set appropriate buffer pool size, enable slow query logs, appropriately increase the number of connections, and check the use of temporary tables; 4. Other optimizations: Reasonably design the table structure, consider partitioning tables, handle lock waiting issues, and maintain tables regularly.
    Mysql Tutorial . Database 198 2025-07-08 01:22:21
  • Managing table partitioning for large datasets in MySQL
    Managing table partitioning for large datasets in MySQL
    Table partitioning is to distribute large tables in multiple physical files according to rules to improve performance. Its importance lies in optimizing queries and simplifying maintenance. When choosing a suitable partition key, you need to consider the data access mode: 1. Priority is used for RANGE partitioning with the time field; 2. Avoid frequent updates of fields; 3. Select hash or list partitions based on common fields for query. Common types include RANGE suitable for dates, LIST for enumeration values, evenly distributed HASH and KEY partitions. During maintenance, partitions need to be added, merged and deleted old data regularly. Note that the partition key should be the primary key part and the query must have a partition key to achieve cropping.
    Mysql Tutorial . Database 894 2025-07-08 01:15:01
  • Backing Up a MySQL Database Using mysqldump
    Backing Up a MySQL Database Using mysqldump
    The basic commands for backing up the database of mysqldump are: mysqldump-u username-p database name> backup file.sql; 1. You can use the --databases parameter for backing up multiple databases at once, such as: mysqldump-u user-p--databasesdb1db2> multi-store backup.sql; 2. You can use the --all-databases parameter for backing up all databases; 3. To save space, you can combine gzip compression, such as: mysqldump-u user-p database|gzip> backup.sql.gz; 4. Automatic backup can be implemented by writing scripts and cooperating with cron timing execution.
    Mysql Tutorial . Database 468 2025-07-08 01:12:41
  • Approaches to Scaling MySQL Database for High Load
    Approaches to Scaling MySQL Database for High Load
    The MySQL stand-alone bottleneck can be solved through read and write separation, library separation, cache and asynchronous processing and other optimization methods. 1. Read and write separation is realized through master-slave replication. The main library processes write requests, and the slave library processes read requests, and combines connection pools to improve efficiency, but attention should be paid to the asynchronous replication delay problem; 2. The sub-repository sub-table includes vertical split (split by field) and horizontal split (split by rules), which is suitable for large data scenarios and requires middleware to handle complex queries; 3. Caching can reduce database pressure, use Redis or Memcached to cache hotspot data, and combines message queues to asynchronously process non-real-time write operations; 4. Other optimizations include slow query analysis, parameter tuning, connection pool management and SQL optimization, and detailed processing is crucial to performance improvement.
    Mysql Tutorial . Database 872 2025-07-08 00:54:41
  • Implementing Full-Text Search Capabilities in MySQL
    Implementing Full-Text Search Capabilities in MySQL
    MySQL supports full-text search, but it needs to be paid attention to its mechanism and limitations. Full-text index is based on "word", supports natural language and Boolean pattern query, and is only applicable to CHAR, VARCHAR and TEXT type columns. 1. Creation methods include adding or adding existing tables when creating tables; 2. Use MATCH() AGAINST() in query, and you can choose natural language or Boolean mode; 3. Notes include the default minimum word length is 4. Chinese word segmentation needs to be processed manually; 4. Limitations include word segmentation problems, performance bottlenecks, update delays and weak fuzzy matching. It is recommended to combine tools such as Elasticsearch to make up for the shortcomings.
    Mysql Tutorial . Database 717 2025-07-08 00:46:31
  • Working with NULL and Three-Valued Logic in MySQL
    Working with NULL and Three-Valued Logic in MySQL
    NULL in MySQL represents an unknown value and cannot be judged by ordinary comparison characters. ISNULL or ISNOTNULL must be used. 1. When NULL participates in comparison, it will not be accepted as TRUE by the WHERE condition; 2. Aggregation functions such as SUM and AVG will ignore NULL, COUNT(*) counts all rows, COUNT(column) does not count NULL; 3. CoALESCE() or IFNULL() can be used to replace the default value; 4. Key fields should be set to NOTNULL when creating tables; 5. Special attention should be paid to the impact of NULL in JOIN and WHERE conditions.
    Mysql Tutorial . Database 530 2025-07-07 02:14:20
  • Handling large object (BLOB/TEXT) data efficiently in MySQL
    Handling large object (BLOB/TEXT) data efficiently in MySQL
    When dealing with large object data in MySQL, you need to pay attention to performance optimization issues. 1. Reasonably select the field type and select TEXT or BLOB subtypes of different capacity according to actual needs to avoid space waste and performance burden; 2. Avoid returning large fields in frequent queries, clearly list the required fields, use overlay indexes, or disassemble large fields to improve efficiency; 3. Optimize storage and IO strategies, such as external storage files, compressed content, partition management and reduce updates to large fields in transactions; 4. Use indexes carefully, TEXT/BLOB needs to specify the prefix length to build an index, reasonably set the prefix length and design the index effectiveness in combination with the query pattern.
    Mysql Tutorial . Database 903 2025-07-07 02:13:21

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