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PolarDB:Overview

Last Updated:Mar 28, 2026

PolarDB for PostgreSQL (Compatible with Oracle) is a cloud-native database service built on a compute-storage separated architecture. All compute nodes share a unified storage layer, enabling minute-level resource scaling, second-level fault recovery, and global data consistency. The service combines the stability, reliability, high performance, and scalability of commercial databases with the simplicity, openness, and rapid iteration of open source cloud databases. It is highly compatible with Oracle syntax, making it a practical migration target for Oracle workloads.

Key capabilities:

CapabilityDetails
Elastic scalingScale compute resources in minutes to handle traffic spikes
Fast fault recoveryRecover from node failures in seconds
Built-in backupData backup and disaster recovery included at no extra cost
Massive read capacityUp to 15 read-only nodes per Enterprise Edition cluster
Oracle compatibilityRun Oracle workloads without rewriting syntax

Architecture

PolarDB for PostgreSQL (Compatible with Oracle) separates compute from storage. Multiple compute nodes share a single distributed storage layer, so:

  • Adding or removing read-only nodes does not require data migration or replication.

  • The primary node and all read-only nodes always read from the same storage, eliminating data synchronization lag.

  • Storage scales independently of compute resources.

Key concepts

TermDefinition
RegionThe geographical area where a PolarDB cluster is deployed.
ZoneA physically separate area within a region, with independent power and networking infrastructure. Instances in the same zone have lower network latency than those in different zones. See Alibaba Cloud's global infrastructure.
ClusterOne primary node plus multiple read-only nodes. Clusters support cross-zone deployments but cannot span multiple regions. Each cluster has a unique ID with the prefix pc.
NodeA physical compute unit within a cluster. Each node has a unique ID with the prefix pi. Nodes of the same type share the same specifications.
Primary nodeThe single read/write node in a cluster. Handles both reads and writes. Also called the read-write node.
Read-only nodeA node that handles read traffic only. Enterprise Edition clusters support up to 15 read-only nodes.

Console

Use the PolarDB console to create, connect to, and configure PolarDB clusters.