Deep Dive into OceanBase HTAP Capabilities and Architecture

1. OceanBase Core Features and Technical Architecture

OceanBase originated in 2010 as an internal Taobao project and has evolved into a fully distributed, multi‑tenant relational database with strong OLTP and HTAP capabilities. It supports MySQL and Oracle compatibility, high performance (7.07 billion tpmC in 2020), high availability (recovery within 8 seconds), high scalability, low storage cost via LSM‑Tree compression, native multi‑tenant isolation, and comprehensive security features.

2. Execution Engine: Performance Optimizations

The execution engine splits SQL plans into fragments (DFOs) for parallel execution, supports both serial and parallel strategies, and adapts to TP or AP workloads. It employs various join strategies (partition join, partial partition join, hash join, broadcast join) and adaptive execution that decides on‑the‑fly whether to build hash tables based on data reduction.

3. Advanced Query Optimizer

OceanBase uses a two‑stage optimizer (serial plan generation followed by parallelization) and, from version 4.0 onward, a three‑stage push‑down strategy that improves complex queries with distinct and aggregation operations.

4. Storage Engine: Row‑Column Hybrid and Compression

The storage engine is based on an LSM‑Tree, enabling write‑only in‑memory updates and background compaction. It stores data in a row‑column hybrid format, allowing column‑wise compression that can reduce disk usage to one‑third or less compared to traditional B‑Tree engines.

5. Resource Isolation

Native multi‑tenant support isolates CPU, memory, and I/O per tenant, preventing heavy AP queries from affecting TP latency. Resource groups can be configured to separate batch and transactional workloads, and physical isolation (read‑write splitting, read‑only replicas) further safeguards TP performance.

6. Fast Import (Direct Path)

Direct Path bypasses the SQL layer and LSM‑Tree memory tier, writing data directly to SSTables for high‑throughput bulk loading (4‑5× faster). It locks tables during import, creates shadow tables, and merges data post‑load.

7. Summary

OceanBase delivers a unified HTAP solution with strong OLTP performance, advanced OLAP capabilities, robust high‑availability, security, and extensive tooling for migration, monitoring, and diagnostics. Ongoing development includes external table support and further performance enhancements.

8. Q&A

Q1: How does OceanBase compare with Snowflake, Doris, ClickHouse? A: Benchmarks are similar; users should conduct their own tests.

Q2: What about security and availability? A: Proven in Ant Group’s core systems with Paxos replication and multi‑tenant isolation.