Mysqlsharding _ MySQL

This article mainly introduces mysqlsharding (fragment). This article describes the Sharding application scenarios and the differences between Sharding and database Partition. For more information, see 1. what are common Sharding application scenarios?

When the amount of data in the database is getting bigger and bigger, both reading and writing will increase the pressure. Imagine that when the data volume in a table reaches tens of millions or even hundreds of millions of data records, both index creation and cache optimization will face huge performance pressure. Sharding distributes data in the same database to multiple databases or machines through certain conditions to reduce the pressure on a single machine.

Online games, IM, and BSP are suitable for Sharding application scenarios;

2. what is the difference between Sharding and database Partition?

Sharding implements Distributed Data deployment. it distributes data to different DB servers through a series of sharding rules and accesses specific databases through routing rules, each access is not a single server, but N servers, which reduces the pressure on a single server.

Partition only implements DB partitions and cannot be deployed across servers.

The word "Shard" means "fragmentation" in English. as a database-related technical term, it seems to have been first seen in massively multiplayer online role-playing games (MMORPG ." Sharding is called "Sharding ".

Sharding is not a new technology, but a relatively simple software concept. As you know, MySQL 5 was used to partition data tables. Before that, many potential MySQL users concerned about MySQL scalability, whether the partition function is available is a key indicator (of course not the only indicator) for measuring the scalability of a database ). Database scalability is an eternal topic. MySQL promoters are often asked: how does one implement partitioning to process application data in a single database? The answer is Sharding.

Sharding is not a function attached to a specific database software, but an abstract processing based on specific technical details. it is a horizontally scalable (Scale Out) solution, its main purpose is to break through the I/O capability limitations of single-node database servers and solve Database scalability problems.