How to shard and partition tables in MySQL?

MySQL sharding refers to splitting a database into multiple libraries, with each library further segmented into multiple tables, in order to enhance the performance and scalability of the database.

The steps for splitting databases and tables are as follows:

1. Database sharding: Splitting the original database into multiple databases based on business logic. They can be divided by business modules, geographic locations, etc., with each database having its own server or cluster.
2. Partitioning: Divide a large table into multiple smaller tables in each database. This can be done based on data range, ID modulus, etc., with each small table storing a portion of the data.
3. Data migration: migrate data from the original database to the corresponding libraries and tables according to the partitioning rules. Data migration can be done using tools or custom scripts.
4. Configure routing: Set up routing rules for sharding and partitioning in the application so that data requests can be automatically directed to the appropriate databases and tables.
5. Index optimization: optimize the indexes for the split databases and tables to enhance query performance.
6. Data consistency: Sharding and splitting databases will increase the difficulty of ensuring data consistency, requiring the design of a reasonable distributed transaction or data synchronization mechanism to ensure data consistency.

It is important to note that sharding and partitioning may not be suitable for all scenarios. They should only be considered when the database performance reaches bottleneck, there is a large amount of data, or high concurrency. Since sharding and partitioning will increase system complexity and maintenance costs, it is necessary to consider business requirements and actual circumstances.