This topic provides an overview of ApsaraDB RDS for PostgreSQL and describes the related terms.

ApsaraDB for RDS is a stable, reliable, and scalable online database service. It is designed based on the Apsara Distributed File System and high-performance SSD storage media of Alibaba Cloud. It supports five database engines: MySQL, SQL Server, PostgreSQL, and MariaDB. It also provides a complete suite of solutions for various scenarios, such as disaster recovery, backup, restoration, monitoring, and migration. These solutions facilitate database operation and maintenance (O&M). For more information about the benefits of ApsaraDB for RDS, see Competitive advantages of ApsaraDB RDS instances over self-managed databases.

You can submit a ticket if you require technical support. If your workloads are complex, you can purchase a support plan on the Alibaba Cloud After-Sales Support page. This allows you to seek advice from instant messaging (IM) enterprise groups, technical account managers (TAMs), and service managers.

For more information about ApsaraDB for RDS, visit the ApsaraDB RDS for MySQL product page.


Some features or functions that are described in this document may be unavailable. For more information, see the specific terms and conditions in your commercial contract. This document serves as a user guide that is for reference only. No content in this document can constitute any expressed or implied warranty.


PostgreSQL is an advanced open source database that is compatible with SQL and supports various data types, such as JSON data, IP data, and geometry data. PostgreSQL supports basic features, such as transactions, subqueries, multi-version concurrency control (MVCC), and data integrity check. In addition to the basic features, PostgreSQL supports the high availability architecture and provides the backup and restoration feature to facilitate database operation and maintenance (O&M). PostgreSQL also provides the following advanced features and functions:

  • ApsaraDB for MyBase dedicated clusters: An ApsaraDB for MyBase dedicated cluster consists of multiple hosts, such as ECS instances of the ecs.i2.xlarge instance type and ECS Bare Metal instances. You can run instances on these hosts. For more information, see What is ApsaraDB for MyBase?
  • Fully encrypted databases: You can create a fully encrypted database on your RDS instance to store data that is uploaded from the user end. Data is encrypted before it is uploaded to the fully encrypted database. The fully encrypted database protects data from internal and external security threats and allows only authorized users to access the data. For more information, see Fully encrypted databases.
  • Read-only RDS instances: If the primary RDS instance is overwhelmed by a large number of read requests, your workloads may be interrupted. In this situation, you can create one or more read-only RDS instances to offload read requests from the primary RDS instance. For more information, see Create a read-only ApsaraDB RDS for PostgreSQL instance. By creating one or more read-only RDS instances, you can scale up the read capability of your database system and increase the throughput of your application.

For more information about the features and functions that ApsaraDB RDS for PostgreSQL supports, see Features of ApsaraDB RDS for PostgreSQL.

Basic terms

  • Instance: An RDS instance is a database process that consumes independent physical memory resources. You can specify a specific memory size, disk capacity, and database type for an RDS instance. The performance of an RDS instance varies based on the specified memory size. After an RDS instance is created, you can change its specifications or delete the instance.
  • Database: A database is a logical unit that is created on an RDS instance. One RDS instance can have multiple databases. Each database must have a unique name on the RDS instance where it is created.
  • Region and zone: Each region is a physical data center. Each region contains a number of isolated locations that are known as zones. Each zone has an independent power supply and network. For more information, visit the Alibaba Cloud's Global Infrastructure page.

General terms

Term Description
On-premises database A database that is deployed in an on-premises data center or a database that is not deployed on an ApsaraDB for RDS instance.
ApsaraDB RDS for XX (XX represents one of the following database engines: MySQL, SQL Server, PostgreSQL, and MariaDB.) ApsaraDB for RDS with a specific database engine. For example, ApsaraDB RDS for MySQL indicates an ApsaraDB for RDS instance that runs MySQL.