AliSQL is an independent MySQL branch that is developed by Alibaba Cloud. AliSQL provides all the features of MySQL. AliSQL also provides enterprise-grade features, such as backup and restoration, monitoring, performance optimization, and read-only instances. This topic provides an overview of the features that are provided by AliSQL. This topic also provides a comparison between AliSQL and other MySQL versions.
RDS for MySQL is built on the AliSQL kernel, an independent branch of MySQL that is heavily customized by Alibaba Cloud. It provides all MySQL features, plus enterprise-grade features such as security, backup, restoration, monitoring, performance optimization, and read-only instances. This document describes the main features of AliSQL and compares it with other MySQL versions.
AliSQL
AliSQL is a MySQL branch maintained by Alibaba Cloud. It enhances the community edition with enterprise-grade features comparable to those in MySQL Enterprise Edition, such as enterprise-grade backup and recovery, a thread pool, and parallel query. AliSQL also offers Oracle-compatible features like the sequence engine.
Feature availability by version
Features
Feature | Description | MySQL versions | |||
8.4 | 8.0 | 5.7 | 5.6 | ||
Lets you use SQL statements to query or restore data to a specific point in time, ensuring quick recovery from accidental operations. | Supported | Supported | Not supported | Not supported | |
Separates threads from sessions using a thread pool, allowing a small number of threads to process tasks from many active sessions. | Supported | Supported | Supported | Supported | |
Stabilizes MySQL execution plans using optimizer and index hints. Includes the DBMS_OUTLN toolkit for easier management. | Supported | Supported | Supported | Not supported | |
Simplifies the generation of sequence values. | Supported | Supported | Supported | Supported | |
Enables DML statements to return a result set. Includes the DBMS_TRANS toolkit for easier management. | Supported | Supported | Not supported | Not supported | |
Encrypts specified data columns to prevent unauthorized access to plaintext data through cloud platform tools. | Not supported | Supported | Supported | Not supported | |
Performance
Feature | Description | MySQL versions | |||
8.4 | 8.0 | 5.7 | 5.6 | ||
Improves query performance with a redesigned cache that overcomes the limitations of the native MySQL query cache. | Not supported | Not supported | Supported | Not supported | |
Writes binary log content to the redo log synchronously on transaction commit, reducing disk I/O and improving database performance. | Supported | Supported | Not supported | Not supported | |
Groups statements into a queue to reduce conflict overhead. Statements likely to conflict, such as those on the same row, are placed in the same bucket. | Supported | Supported | Supported | Not supported | |
Enables rapid transaction commits and rollbacks. Using it with the returning and statement queue features significantly improves business throughput. | Supported | Supported | Supported | Supported | |
Improves database write performance in high-concurrency scenarios by writing binary logs in parallel during transaction commits. | Supported | Supported | Not supported | Not supported | |
Stability
Feature | Description | MySQL versions | |||
8.4 | 8.0 | 5.7 | 5.6 | ||
Offers statement-level concurrency control (CCL). Includes the DBMS_CCL toolkit for easier management. | Supported | Supported | Supported | Not supported | |
A MySQL plug-in that collects and aggregates internal performance metrics from an instance. | Supported | Supported | Supported | Supported | |
Ensures system stability by deleting large files asynchronously. | Supported | Supported | Supported | Supported | |
A powerful tool for instance-level workload monitoring, correlation analysis, and performance tuning. It helps you quickly assess database loads, find the root cause of performance issues, and improve database stability. | Supported | Supported | Supported | Not supported | |
Optimizes the binary log writing stage for large transaction commits. This prevents long write times, instance stalls, and hangs, which improves instance stability. | Supported | Supported | Supported | Not supported | |
DDL optimization
Feature | Description | MySQL versions | |||
8.4 | 8.0 | 5.7 | 5.6 | ||
Instantly adds columns by only modifying metadata, which avoids a full table rebuild. This fast, resource-efficient, and non-blocking operation is ideal for environments that require frequent schema changes. | Supported | Supported | Supported | Not supported | |
Instantly modifies a column's data type by changing only metadata, which avoids a full table copy. This reduces operation time and improves O&M efficiency. | Supported | Supported | Not supported | Not supported | |
Instantly modifies a column's character set by changing only metadata, which avoids a table rebuild. This reduces operation time and improves O&M efficiency. | Supported | Supported | Supported | Not supported | |
Performs column type modifications at the InnoDB engine layer, allowing online changes without blocking read and write operations. | Supported | Supported | Supported | Not supported | |
Improves the handling of unique key conflicts during DDL execution to reduce failures and increase the success rate. | Supported | Supported | Not supported | Not supported | |
Lets you set BPS and IOPS limits for DDL operations to control their I/O resource consumption and ensure workload stability. | Supported | Supported | Not supported | Not supported | |
Prevents DDL operations from blocking sessions if an MDL lock cannot be acquired promptly. This avoids connection buildup and improves instance stability and availability. | Supported | Supported | Not supported | Not supported | |
Lets you use hints to control the MDL lock wait timeout for DDL threads, which helps prevent session blocking and connection buildup from long waits. | Supported | Supported | Not supported | Not supported | |
Optimizes the buffer pool management mechanism during DDL operations to reduce their performance impact and increase the concurrency of online DDL operations. | Supported | Supported | Supported | Supported | |
Moves deleted tables to a recycle bin with a configurable retention period for easy data recovery. Includes the DBMS_RECYCLE toolkit for easier management. | Supported | Supported | Supported | Not supported | |
Replication optimization
Feature | Description | MySQL versions | |||
8.4 | 8.0 | 5.7 | 5.6 | ||
Optimizes parallel replication wait logic to eliminate lag during batch data processing. Ideal for off-peak batch deletion, reorganization, or data import tasks. | Supported | Supported | Not supported | Not supported | |
Streams binary logs to secondary instances during large transaction execution. This prevents semi-synchronous replication from timing out and degrading to asynchronous mode, ensuring high data reliability and stable performance. | Supported | Supported | Not supported | Not supported | |
Allows primary and secondary instances to execute DDL operations concurrently by notifying the secondary when the primary begins. This virtually eliminates DDL-related replication lag and ensures high availability. | Supported | Supported | Not supported | Not supported | |
Allows primary and secondary instances to execute large transactions concurrently by notifying the secondary when the primary begins. This virtually eliminates replication lag and ensures high availability. | Not supported | Supported | Not supported | Not supported | |
Optimizes the lock wait logic between I/O, SQL, and worker threads to reduce lock waits, which virtually eliminates replication lag for high-concurrency small transactions. | Not supported | Supported | Not supported | Not supported | |
Features
Category | Feature | Community edition | Enterprise edition | AliSQL | Alibaba Cloud RDS for MySQL |
Enterprise value-added services | Not available | √ | √ | √ | |
Not available | √ | √ | √ | ||
Not available | √ | √ | √ | ||
MySQL features | √ | √ | √ | √ | |
MySQL connectors | √ | √ | Supports public releases | Supports public releases | |
MySQL replication | √ | √ | √ | √ | |
MySQL router | √ | √ | MaxScale (supported in MySQL 8.0) | single-tenant database proxy | |
MySQL partitioning | √ | √ | √ | √ | |
InnoDB MyISAM NDB | InnoDB MyISAM NDB | InnoDB X-Engine | InnoDB X-Engine | ||
Oracle compatibility | Not available | Not available | Supported in MySQL 8.0 | Supported in MySQL 8.0 | |
MySQL enterprise monitor | Not available | √ | In development | Enhanced Monitor | |
Not available | √ | In development | Performance Insight | ||
Not available | √ | In development | √ | ||
Not available | Not available | Not available | Enhanced Monitor | ||
MySQL enterprise backup | Not available | √ | √ | √ | |
Not available | √ | √ | database and table-level backup | ||
Not available | √ | √ | database and table-level restoration | ||
Not available | √ | √ | √ | ||
Not available | Not available | Not available | cross-region backup | ||
Not available | Not available | Supported in MySQL 8.0 | Supported in MySQL 8.0 | ||
Not available | Not available | √ | √ | ||
MySQL enterprise security | Local key replacement | √ | BYOK TDE, key rotation | BYOK TDE, key rotation | |
Not available | Not available | Not available | BYOK encryption at rest | ||
SSL | √ | SSL | SSL | ||
Not available | √ | SQL Insights | SQL Insights | ||
SM4 encryption algorithm | Not available | Not available | √ | √ | |
Not available | Not available | Supported in MySQL 5.7 | Supported in MySQL 5.7 | ||
MySQL enterprise scalability | Not available | √ | Supported in MySQL 8.0 | Supported in MySQL 8.0 | |
Not available | Not available | √ | read-only instance | ||
MySQL enterprise reliability | Not available | Not available | √ | √ | |
Not available | Not available | √ | √ | ||
Not available | Not available | √ | √ | ||
Not available | Not available | √ | √ | ||
MySQL enterprise high-availability | Not available | Not available | A third-party HA mechanism is required. | High-availability Edition | |
√ | √ | √ | High availability for read-only instances |