Alibaba Cloud customizes database engines based on the community editions of native MySQL and PostgreSQL to provide more advanced features.


AliSQL is an independent MySQL branch that is developed by Alibaba Cloud. AliSQL provides all the features of the MySQL Community Edition. AliSQL also provides some similar features that you can find in the MySQL Enterprise Edition. These similar features include enterprise-grade backup and restoration, thread pool, and parallel query. In addition, AliSQL provides Oracle-compatible features, such as the Sequence engine. ApsaraDB RDS for MySQL with AliSQL provides all features of MySQL and a wide range of advanced features that are developed by Alibaba Cloud. These advanced features include enterprise-grade security, backup and restoration, monitoring, performance optimization, and read-only instances.

AliSQL provides a number of innovative features that are designed to improve functionality, performance, stability, and security, including:

  • Thread Pool

    This feature uses the Listener-Worker model to improve the connection performance of AliSQL. It optimizes the concurrency control for different types of operations based on their priorities. This allows ApsaraDB for RDS to ensure high performance when it processes a large number of concurrent requests.

  • Statement outline

    This feature uses optimizer and index hints to ensure the stability of ApsaraDB for RDS when SQL query plans change due to data update, index addition or deletion, or parameter adjustment.

  • Fast query cache

    The fast query cache is developed by Alibaba Cloud based on the native MySQL query cache. The fast query cache uses a new design and implementation mechanism to increase the query performance of ApsaraDB for RDS. The fast query cache also optimizes concurrency control, memory management, and caching.

  • Binlog in Redo

    This feature synchronously writes binary logs to the redo log file when a transaction is committed. This reduces operations on disks and improves database performance.

  • Faster DDL

    This feature is developed by the ApsaraDB for RDS team. It fixes defects in the cache maintenance logic that is used to manage data definition language (DDL) operations. It also provides the optimized buffer pool management mechanism to reduce competition for locks that are triggered by DDL operations. This feature ensures the DDL operation performance of ApsaraDB for RDS when it processes a regular number of requests.

For more information, see Overview of AliSQL features.


Alibaba Cloud offers two PostgreSQL-compatible database services that run AliPG: ApsaraDB RDS and ApsaraDB for MyBase. AliPG is a unified database engine that is developed by Alibaba Cloud. Since the commercial rollout of AliPG in 2015, AliPG has been running stably for years and processed a large volume of workloads within Alibaba Group and for Alibaba Cloud customers. AliPG supports the following major PostgreSQL versions: 9.4, 10, 11, 12, 13 and 14.

AliPG has the following advantages over open source PostgreSQL:

  • Faster speed
  • Higher stability

    AliPG uses the Platform as a Service (PaaS) architecture. This architecture allows you to transform traditional software from license-based services to subscription-based services. You can manage a large amount of metadata, optimize connections, and efficiently isolate resources. In addition, each RDS instance supports tens of thousands of schemas.

  • Higher security
    • AliPG is certified based on leading national and international security standards, which empowers enterprises to increase institutional security scores in the financing and listing phases.
    • AliPG provides the following security enhancements:
      • Encrypts sensitive data that contains passwords. The sensitive data includes dynamic views, shared memory, the dblink plug-in, historical commands, and audit logs.
      • Fixes the function-related bugs that are found in open source PostgreSQL.
      • Supports fully encrypted databases. For more information, see Fully encrypted databases.
      • Supports the semi-synchronous mode. This mode allows you to specify one of the following protection levels for your RDS instance: maximum protection, maximum availability, and maximum performance. For more information, see Set the protection level of an ApsaraDB RDS for PostgreSQL instance.
      • Supports the failover slot feature. This feature prevents primary/secondary switchovers from affecting the reliability of logical replication. For more information, see Logical Replication Slot Failover.
  • Higher flexibility and controllability. For more information, see What is ApsaraDB for MyBase?
    • AliPG grants you the permissions to manage the operating systems on hosts in dedicated clusters.
    • AliPG allows you to customize overcommit ratios in the development, test, and staging environments. For example, you can specify 128 cores for a host that provides only 64 cores. This way, you can exclusively occupy resources in the production environment to reduce the overall costs.

For more information about the features of AliPG, see Functional modules of AliPG.