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catalogue redis data storage Data structure and coding string embstr Comparison between embstr and raw sds Differences between sds and c language strings: list quicklist structure diagram: set zset Implementation principle of zskiplist skiplist query process hash hash structure summary redis data storage redis is an in memory ...

1. What is a data connection pool Database connection pool( Database Connection Pooling)When the program is initialized, a certain number of database connection objects are created and saved in a memory area, which allows the application to reuse an existing database connection instead of re establishing one; Release the database connection ...

Introduction to MongoDB concept MongoDB is an open source database system based on distributed file storage. MongoDB is a product between relational database and non relational database. It is the most functional and relational database among non relational databases. MongoDB is characterized by no Schema restrictions and high flexibility. T ...

catalogue 1, What is JDBC 2, Working principle and advantages of JDBC 3, JDBC Usage Summary 1. Create database Connection 2. Create operation command Statement 3. Use the operation command to execute SQL 4. Process ResultSet 5. Release resources Specific implementation code: 4, JDBC common interfaces and classes 1.JDBC API 2. Databa ...

1-3 See blog Detailed explanation of Redis - publish and subscribe (Part I) 4 send message When a Redis client executes the PUBLISH command to send a message to the channel, the server needs to perform the following two actions: 1) send message to all subscribers of channel channel. 2) If one or more patterns match the channel, the messa ...

Case has two formats: simple case function and case search function. – simple Case function The function of a simple Case expression is to use the expression to determine the return value: select id,name, case sex when '1' then 'male' when '2' then 'female' else 'other' end from student – search Case function: Case function (c ...

1, Input / output class (1) PHP realizes search and query function 1. After obtaining the data input by users, the website connects to the database to retrieve the information input by users, and then returns the search results to users, so as to realize the function of search and query. 2. Code example (1) index home page, search box <!DOC ...

🏷️ The current chapter is [MySQL basics] 07: view 🤖 🏷️ More: MySQL basic tutorial , take you to start MySQL database on a zero basis! 💪 🏷️ Welcome to praise 👍 Collection 🌟 Attention ❤️ Leaving a message. ✍️ Concept of view A virtual table composed of data queried by one or more tables in a database according to specific cond ...

1, Database connection pool 1. What is a database connection pool Database connection pool is responsible for allocating, managing and releasing database connections. It allows applications to reuse an existing database connection instead of re establishing one; Release the database connection whose idle time exceeds the maximum idle time ...

ODBC benefits Good portability Can access different databases at the same time Share multiple data resources ODBC overview Causes of ODBC Due to the existence of different database management systems, applications written under one relational database management system can not run under another relational database management system Many app ...