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

If you require technical support, log on to the ApsaraDB for RDS console. In the top navigation bar, choose Tickets > Submit Ticket. If your business is complex, you can purchase a support plan 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.


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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 Create a fully encrypted database on an ApsaraDB RDS for PostgreSQL instance.
  • 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 instance is a database service process that separately consumes physical memory resources. You can set a specific memory size, disk capacity, and database type. The memory size determines the performance of the instance. After an instance is created, you can change the specifications or delete the instance.
  • Database: A database is a logical unit created on an instance. The name of each database on the same instance must be unique.
  • Region and zone: Each region is a physical data center. Each region contains many isolated locations known as zones. Each zone has an independent power supply and network. For more information, see Alibaba Cloud's Global Infrastructure.

General terms

Term Description
On-premises database A database that is deployed to an on-premises data center or 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, PPAS, and MariaDB.) ApsaraDB for RDS with a specific database engine. For example, ApsaraDB RDS for MySQL means the database engine of the instance enabled on ApsaraDB for RDS is MySQL.