All Products
Search
Document Center

PolarDB:Introduction

Last Updated:Mar 28, 2026

PolarDB for PostgreSQL (Compatible with Oracle) is a cloud-native relational database that lets you run Oracle-compatible workloads on Alibaba Cloud without rewriting your application code.

If your team already works with Oracle syntax — data types, stored procedures, system views, database links, partitioned tables, and partitioned indexes — PolarDB for Oracle works the same way. To migrate from Oracle, use Advanced Database & Application Migration (ADAM), an intelligent migration tool that handles assessment, data synchronization, compatibility testing, and performance comparison across the full migration lifecycle.

PolarDB for Oracle is deployed across finance, energy, telecommunications, public services, new retail, and education.

Why switch from Oracle

Replication latency of only a few milliseconds

PolarDB for Oracle uses shared storage and physical logs to keep read-only nodes within a few milliseconds of the primary node. For workloads that require strict data consistency, strong consistency mode is available — though it reduces write throughput to guarantee it.

Run analytics and transactions side by side

Analytical and transactional workloads run on separate, physically isolated read-only nodes, so a heavy analytical query never slows down transaction processing. Distributed parallel computing runs a single SQL query across multiple read-only nodes simultaneously, increasing shared storage I/O throughput and fully using the CPU and memory of each node. When compute capacity runs short, add nodes on demand — no data reallocation required.

Smarter query execution

A next-generation cost-based optimizer generates more accurate execution plans, reducing slow queries caused by plan misestimates across diverse workload patterns.

Kernel-level customization

PolarDB for Oracle is tuned at the kernel level for specific high-demand scenarios such as flash sales and connection pools, so you get optimized behavior without application-level workarounds.

Enterprise-grade security and performance

The architecture and kernel have been deeply optimized, delivering more than twice the performance. Transmission links and stored data are both protected with enterprise-grade encryption. Each cluster runs on a storage and compute separation architecture with one primary node and up to 15 read-only nodes, backed by up to 500 TB of storage per cluster.

Scale on demand

Scale your cluster up or down based on actual workload. Upgrade instance specifications when traffic grows, or downgrade when demand drops — without pre-provisioning hardware capacity you don't need. You pay only for the resources you use.

Migrate from Oracle without rewriting code

PolarDB for Oracle supports the Oracle syntax that database administrators and developers use daily, so your existing queries, stored procedures, and application logic run as-is.

ADAM provides structured, end-to-end migration support:

PhaseWhat ADAM provides
Pre-migrationDatabase and application assessment
During migrationData synchronization and verification, SQL compatibility testing for Java applications
Post-migrationPerformance comparison against your Oracle baseline