MySQL query performance optimization needs to start from the core points, including rational use of indexes, optimization of SQL statements, table structure design and partitioning strategies, and utilization of cache and monitoring tools. 1. Use indexes reasonably: Create indexes on commonly used query fields, avoid full table scanning, pay attention to the combined index order, do not add indexes in low selective fields, and avoid redundant indexes. 2. Optimize SQL queries: Avoid SELECT*, do not use functions in WHERE, reduce subquery nesting, and optimize paging query methods. 3. Table structure design and partitioning: select paradigm or anti-paradigm according to read and write scenarios, select appropriate field types, clean data regularly, and consider horizontal tables to divide tables or partition by time. 4. Utilize cache and monitoring: Use Redis cache to reduce database pressure and enable slow query

CTEs are a feature introduced by MySQL8.0 to improve the readability and maintenance of complex queries. 1. CTE is a temporary result set, which is only valid in the current query, has a clear structure, and supports duplicate references; 2. Compared with subqueries, CTE is more readable, reusable and supports recursion; 3. Recursive CTE can process hierarchical data, such as organizational structure, which needs to include initial query and recursion parts; 4. Use suggestions include avoiding abuse, naming specifications, paying attention to performance and debugging methods.

MySQL's EXPLAIN is a tool used to analyze query execution plans. You can view the execution process by adding EXPLAIN before the SELECT query. 1. The main fields include id, select_type, table, type, key, Extra, etc.; 2. Efficient query needs to pay attention to type (such as const, eq_ref is the best), key (whether to use the appropriate index) and Extra (avoid Usingfilesort and Usingtemporary); 3. Common optimization suggestions: avoid using functions or blurring the leading wildcards for fields, ensure the consistent field types, reasonably set the connection field index, optimize sorting and grouping operations to improve performance and reduce capital

The aggregation function is used to perform calculations on a set of values ??and return a single value. Common ones include COUNT, SUM, AVG, MAX, and MIN; GROUPBY groups data by one or more columns and applies an aggregation function to each group. For example, GROUPBYuser_id is required to count the total order amount of each user; SELECTuser_id, SUM(amount)FROMordersGROUPBYuser_id; non-aggregated fields must appear in GROUPBY; multiple fields can be used for multi-condition grouping; HAVING is used instead of WHERE after grouping; application scenarios such as counting the number of classified products, maximum ordering users, monthly sales trends, etc. Mastering these can effectively solve the number

MySQLQueryCache is a built-in caching mechanism used to cache query statements and their results to improve the performance of duplicate queries. 1. It avoids repeated execution of the same query by directly returning cached results; 2. The cache is based on a complete SQL statement, and statement differences or table data changes will cause cache failure; 3. MySQL8.0 has completely removed this function due to poor concurrency performance, low hit rate and high maintenance costs; 4. Alternative solutions include using Redis/Memcached, database middleware ProxySQL, page cache and other more flexible and efficient caching strategies.

Temporary tables are tables with limited scope, and memory tables are tables with different storage methods. Temporary tables are visible in the current session and are automatically deleted after the connection is disconnected. Various storage engines can be used, which are suitable for saving intermediate results and avoiding repeated calculations; 1. Temporary tables support indexing, and multiple sessions can create tables with the same name without affecting each other; 2. The memory table uses the MEMORY engine, and the data is stored in memory, and the restart is lost, which is suitable for cache small data sets with high frequency access; 3. The memory table supports hash indexing, and does not support BLOB and TEXT types, so you need to pay attention to memory usage; 4. The life cycle of the temporary table is limited to the current session, and the memory table is shared by all connections. When choosing, it should be decided based on whether the data is private, whether high-speed access is required and whether it can tolerate loss.

The latest version of Binance is v2.102.5, and the update tutorial is: 1. Click the download link in the web page; 2. Authorize the installation permission of "Allow installation from unknown sources"; 3. Find the downloaded APk and click to install; 4. Click the installed application to open it.

The security of remote access to MySQL can be guaranteed by restricting permissions, encrypting communications, and regular audits. 1. Set a strong password and enable SSL encryption. Force-ssl-mode=REQUIRED when connecting to the client; 2. Restrict access to IP and user rights, create a dedicated account and grant the minimum necessary permissions, and disable root remote login; 3. Configure firewall rules, close unnecessary ports, and use springboard machines or SSH tunnels to enhance access control; 4. Enable logging and regularly audit connection behavior, use monitoring tools to detect abnormal activities in a timely manner to ensure database security.