PolarDB-X
activeby Alibaba Cloud · since 2021 · also known as PolarDB Distributed Edition, DRDS
Alibaba's open-source, MySQL-compatible shared-nothing distributed SQL with Paxos and columnar indexes.
Overview
PolarDB-X is Alibaba Cloud's distributed edition of PolarDB, descended from the DRDS sharding middleware that ran Taobao's Double-11 traffic. Stateless compute nodes (written in Java) parse MySQL-dialect SQL and route it to data nodes based on a MySQL fork with X-Paxos replication, while global secondary indexes and clustered columnar indexes keep cross-shard lookups and analytics workable. The engine is open source under Apache 2.0 and installable with Kubernetes operators, and it is also sold as a managed service. It is a credible alternative to TiDB and OceanBase for MySQL shops that need horizontal scale, mainly within the Alibaba ecosystem.
Strengths & trade-offs
Strengths
- +MySQL-compatible SQL and a MySQL-format global binlog for downstream tools
- +Global secondary indexes avoid scatter-gather lookups on non-shard keys
- +Clustered columnar indexes add analytical scans without a separate warehouse
- +X-Paxos replicas give RPO=0 within a region
- +Apache 2.0 open source with Kubernetes operator
Trade-offs
- −Ecosystem and docs centered on Alibaba Cloud and Chinese-language community
- −No triggers; some MySQL features behave differently across shards
- −More moving parts (CN, DN, GMS, CDC, columnar) than single-node MySQL
- −Version numbering and release cadence of the open-source edition are hard to track
Great for
- +Scaling large MySQL e-commerce databases
- +High-concurrency order and payment systems
- +Consolidating sharded MySQL into one logical database
- +Operational analytics via columnar indexes
Think twice for
- −Small single-instance MySQL workloads
- −Teams outside the Alibaba ecosystem wanting a large Western community
- −Apps relying on MySQL triggers
Capabilities
Native or official first-party support · 14 of 25 tracked
Scale & consistency
- Comfortable data size
- Large · ≤ 1 PB
- Horizontal scaling
- Native
- Multi-region
- Read replicas
- Transactions
- Full ACID
- Consistency
- Strong
- Schema
- Strict
- Architecture
- Distributed, Client server
- Query languages
- SQL
Hash/range partitioning with automatic rebalancing; data nodes use three-replica X-Paxos; cross-region via read-only instances and CDC.
Deployment
available on · Alibaba Cloud
Ecosystem
Alternatives to PolarDB-X
MySQL-compatible distributed SQL with a row store for OLTP and a columnar replica for real-time analytics.
polardb-x vs tidb →Alipay-proven distributed SQL with MySQL (and Oracle, in Enterprise) compatibility, HTAP and vector search.
polardb-x vs oceanbase →CNCF-graduated sharding and clustering layer that makes a fleet of MySQL servers look like one database.
polardb-x vs vitess →Alibaba Cloud's shared-storage relational service in MySQL-, PostgreSQL- and Oracle-compatible editions.
polardb-x vs polardb →Apache sharding middleware that adds sharding, read/write splitting and encryption over MySQL or Postgres.
polardb-x vs apache-shardingsphere →Tencent's financial-grade MySQL-compatible database family: distributed TDSQL and cloud-native TDSQL-C.
polardb-x vs tencent-tdsql →PolarDB-X FAQ
What is PolarDB-X?
PolarDB-X is a relational database by Alibaba Cloud, first released in 2021. PolarDB-X is Alibaba Cloud's distributed edition of PolarDB, descended from the DRDS sharding middleware that ran Taobao's Double-11 traffic. Stateless compute nodes (written in Java) parse MySQL-dialect SQL and route it to data nodes based on a MySQL fork with X-Paxos replication, while global secondary indexes and clustered columnar indexes keep cross-shard lookups and analytics workable. The engine is open source under Apache 2.0 and installable with Kubernetes operators, and it is also sold as a managed service. It is a credible alternative to TiDB and OceanBase for MySQL shops that need horizontal scale, mainly within the Alibaba ecosystem.
Is PolarDB-X open source?
Yes. PolarDB-X is open source. License: Apache License 2.0.
Does PolarDB-X support ACID transactions?
Yes. PolarDB-X supports full ACID transactions, with strong consistency.
Does PolarDB-X scale horizontally?
PolarDB-X scales horizontally out of the box, with built-in sharding or partitioning. It is comfortable at large scale (≤ 1 PB). It supports cross-region read replicas.
How can I run PolarDB-X?
You can self-host it and use the vendor's managed cloud. It is available on Alibaba Cloud.
What is PolarDB-X best for?
PolarDB-X is a strong fit for scaling large MySQL e-commerce databases; high-concurrency order and payment systems; and consolidating sharded MySQL into one logical database. Think twice for small single-instance MySQL workloads.
What are the best alternatives to PolarDB-X?
Common alternatives to PolarDB-X include TiDB, OceanBase, Vitess, Alibaba PolarDB and Apache ShardingSphere. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.
How popular is PolarDB-X?
PolarDB-X ranks #391 of 844 databases on the WhichDB Score (5.0/100), and #124 among relational databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.