How to properly optimize database queries? Mastering MySQL design conventions allows technical students to get twice the result with half the effort!

How to correctly optimize database queries? Mastering MySQL design conventions allows technical students to get twice the result with half the effort!

With the rapid development of the Internet, the era of big data has arrived. As an important storage and management tool for data, database performance optimization and query efficiency are crucial to system stability and user experience. This article will introduce how to correctly optimize database queries and help technical students get twice the result with half the effort by mastering MySQL design conventions.

1. Reasonable design of data model

Reasonable data model design is the basis for database optimization. When designing data tables, follow the first, second, and third paradigms, and perform appropriate redundant designs based on specific business needs.

1. First normal form: Each field is atomic and cannot be decomposed.
2. Second Normal Form: Each non-primary key field is completely dependent on the primary key.
3. Third normal form: Each non-primary key field does not depend on other non-primary key fields.

By following the standardized data model design, data redundancy and data update complexity can be reduced, and the query efficiency of the database can be improved.

2. Reasonable use of indexes

Indexes are an important means to improve database query efficiency. Creating appropriate indexes can speed up the query process and reduce the time of full table scans.

1. Choose appropriate index fields: Index fields should be highly selective, that is, unique or highly distinguishable. Generally speaking, primary keys, foreign keys and fields frequently used in queries are suitable index fields.
2. Avoid too many indexes: Although indexes can improve query efficiency, too many indexes will increase data storage space and update time. Index fields should be selected reasonably based on specific business needs to avoid overuse.
3. Optimize the index regularly: As data is added and deleted, the efficiency of the index will also decrease. Indexes need to be optimized and rebuilt regularly to ensure stable query efficiency.

3. Reasonable analysis of query statements

When writing query statements, the efficiency and performance of the query must be fully considered.

1. Avoid excessive joins and subqueries: Join operations and subqueries may cause performance degradation in some cases. Excessive join and subquery operations should be avoided as much as possible, and query statements can be optimized by properly designing the data model and using appropriate indexes.
2. Use appropriate functions and operators: Using appropriate functions and operators in query statements can reduce query time and resource consumption.
3. Avoid using wildcard characters: Wildcard characters such as % and _ will cause a full table scan and lower query efficiency. You should try to avoid using wildcard queries, or use indexes to improve query efficiency.

4. Reasonable optimization of database parameters

The parameter settings of the database also have a certain impact on query efficiency. Reasonable database parameter settings can improve query performance and efficiency.

1. Memory configuration: Reasonable memory configuration can improve the cache effect of the database, reduce query disk IO, and improve query efficiency. You can optimize the cache effect by setting parameters such as innodb_buffer_pool_size and join_buffer_size.
2. Concurrent configuration: Concurrent configuration can improve the concurrent access capability of the database and improve query efficiency. Concurrency configuration can be optimized by setting parameters such as max_connections and innodb_thread_concurrency.
3. Log configuration: Reasonable log configuration can improve the recovery capability and fault handling capabilities of the database. Log configuration can be optimized by setting binlog_format, log_bin and other parameters.

Summary:

Correctly optimizing database queries is an important part of improving system performance and user experience. By properly designing the data model, using appropriate indexes, analyzing query statements and optimizing database parameters, the query efficiency of the database can be greatly improved. When technical students master the design specifications of MySQL, they can optimize database queries with twice the result and ensure the stability and efficiency of the system.

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