Function Overview

Distributed Database Middleware (DDM) is a MySQL-compatible, distributed middleware service designed for relational databases. It can resolve distributed scaling issues to break through capacity and performance bottlenecks of traditional databases, helping handle highly concurrent access to massive volumes of data.

Table 1 lists the functions supported by DDM.

**Table 1** DDM functions
Category	Function
Permissions	Creating a user and granting the user permissions to use DDM and DDM custom policies. For details, see Permissions Management.
Instances	Creating, deleting, and restarting a DDM instance, and changing class of a DDM instance. For details, see Instance Management.
Backups	Restoring data to a new DDM instance and restoring metadata. For details, see Backups and Restorations.
Parameter templates	Creating, editing, replicating, and applying a parameter template, and comparing two parameter templates. For details, see Parameter Template Management.
Task center	Enabling you to view progress and statuses of asynchronous tasks submitted on the console. For details, see Task Center.
Schemas	Creating, exporting, importing, and deleting schemas. For details, see Schema Management.
Shard configuration	You can increase shards or data nodes to scale out storage. For details, see Shard Configuration.
Data nodes	Managing data nodes is managing RDS for MySQL instances that are associated with your DDM instance. You can configure read weights, synchronize data node information, and enable read/write splitting. For details, see Data Nodes.
Accounts	Creating, modifying, and deleting a DDM account, and resetting its password. For details, see Account Management.
Data migration	Migrating data from Huawei Cloud to DDM, a third-party cloud to DDM or exporting data from DDM. For details, see Data Migration.
Monitoring	Providing metrics and methods of viewing metrics. For details, see Monitoring and Alarm Reporting.
Tags	Using tags to manage resources on the management console. For details, see Tags.
SQL syntax	Describing DDL, DML, global sequence, SQL statements, and sharding algorithms. For details, see SQL Syntax.