Which one is more difficult to learn, redis or mysql?
Many friends are confused whether to learn redis or mysql when learning databases. Today I will tell you about the difference and difficulty between the two.
1. Summary of the differences between redis and mysql
Type wise
In terms of type, mysql is a relational database and redis is a cache database
Function
Mysql is used to store data persistently on the hard disk. It is powerful but slow.
Redis is used to store frequently used data in the cache. Fast reading speed
Requirements
Mysql and redis are generally used together due to different needs. (redis tutorial)
2. Detailed description
1. Mysql and redis database types
mysql It is a relational database, mainly used to store persistent data. It stores data on the hard disk and has slow reading speed.
redis is NOSQL, which is a non-relational database and a cache database. It stores data in the cache. The cache has fast reading speed and can greatly improve operating efficiency, but the storage time is limited
2. Mysql operating mechanism
As a relational database with persistent storage, the relative weakness of mysql is that every time a request is made to access the database, there are I/O operations. If the database is accessed repeatedly and frequently. First: it will take a lot of time to repeatedly connect to the database, resulting in too slow operating efficiency; second: repeated access to the database will also cause the database load to be too high, so the concept of caching is derived at this time.
3. Cache
The cache is the buffer (cache) for data exchange. When the browser performs a request, it will first search in the cache. If it exists, it will be obtained; otherwise, it will be retrieved. Access the database.
The advantage of caching is that the reading speed is fast
4.redis database
The redis database is a cache database used to store frequently used data, thus reducing access to the database times to improve operating efficiency.
3. Difficulty level
It can be said that redis is simpler than mysql, but due to project needs, the two are often used in combination. If you learn one database well, others will be easy to understand.
The above is the detailed content of Which one is more difficult to learn, redis or mysql?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



Redis cluster mode deploys Redis instances to multiple servers through sharding, improving scalability and availability. The construction steps are as follows: Create odd Redis instances with different ports; Create 3 sentinel instances, monitor Redis instances and failover; configure sentinel configuration files, add monitoring Redis instance information and failover settings; configure Redis instance configuration files, enable cluster mode and specify the cluster information file path; create nodes.conf file, containing information of each Redis instance; start the cluster, execute the create command to create a cluster and specify the number of replicas; log in to the cluster to execute the CLUSTER INFO command to verify the cluster status; make

How to clear Redis data: Use the FLUSHALL command to clear all key values. Use the FLUSHDB command to clear the key value of the currently selected database. Use SELECT to switch databases, and then use FLUSHDB to clear multiple databases. Use the DEL command to delete a specific key. Use the redis-cli tool to clear the data.

Using the Redis directive requires the following steps: Open the Redis client. Enter the command (verb key value). Provides the required parameters (varies from instruction to instruction). Press Enter to execute the command. Redis returns a response indicating the result of the operation (usually OK or -ERR).

Redis uses a single threaded architecture to provide high performance, simplicity, and consistency. It utilizes I/O multiplexing, event loops, non-blocking I/O, and shared memory to improve concurrency, but with limitations of concurrency limitations, single point of failure, and unsuitable for write-intensive workloads.

To read a queue from Redis, you need to get the queue name, read the elements using the LPOP command, and process the empty queue. The specific steps are as follows: Get the queue name: name it with the prefix of "queue:" such as "queue:my-queue". Use the LPOP command: Eject the element from the head of the queue and return its value, such as LPOP queue:my-queue. Processing empty queues: If the queue is empty, LPOP returns nil, and you can check whether the queue exists before reading the element.

Using Redis to lock operations requires obtaining the lock through the SETNX command, and then using the EXPIRE command to set the expiration time. The specific steps are: (1) Use the SETNX command to try to set a key-value pair; (2) Use the EXPIRE command to set the expiration time for the lock; (3) Use the DEL command to delete the lock when the lock is no longer needed.

Redis uses hash tables to store data and supports data structures such as strings, lists, hash tables, collections and ordered collections. Redis persists data through snapshots (RDB) and append write-only (AOF) mechanisms. Redis uses master-slave replication to improve data availability. Redis uses a single-threaded event loop to handle connections and commands to ensure data atomicity and consistency. Redis sets the expiration time for the key and uses the lazy delete mechanism to delete the expiration key.

The best way to understand Redis source code is to go step by step: get familiar with the basics of Redis. Select a specific module or function as the starting point. Start with the entry point of the module or function and view the code line by line. View the code through the function call chain. Be familiar with the underlying data structures used by Redis. Identify the algorithm used by Redis.
