Overview

This document describes how to buy a DDM instance that meets your service requirements and complete relevant settings based on Huawei Cloud DDM practices.

**Table 1** DDM best practices
Service	Reference	Description
DDM	Formulating Sharding Rules	Selecting a sharding key and algorithm when creating a sharded table
	Determining the Number of Shards in a Schema	Determining the number of shards when creating a sharded schema
	Using Broadcast and Unsharded Tables	Broadcast and unsharded tables
	Transaction Models	DDM transaction models
	SQL Standards	SQL Standards
	Migrating an Entire RDS Database to DDM	Migrating an entire RDS database to a DDM database
	Migrating an Entire MyCat Database to DDM	Migrating an entire MyCat database to DDM
	Accessing DDM Using a JDBC Connection Pool	Accessing DDM using the JDBC connection pool to perform data operations
	Logging In to a DDM Instance Using Navicat	Obtaining an EIP and using this EIP to connect to a DDM instance through the Navicat client
	Migrating Data from RDS for MySQL to DDM Using DRS	Migrating data from RDS for MySQL to DDM using DRS
	Sharding Database and Table Data of an RDS for MySQL Instance	Sharding database and table data of existing RDS for MySQL instances using DDM
	Cross-Shard Complex SQL Tuning	Optimizing cross-shard complex SQL statements