TiDB vs YugabyteDB

TiDB and YugabyteDB are both distributed SQL databases designed to scale relational workloads horizontally. TiDB is MySQL-compatible with unique HTAP capabilities. YugabyteDB is PostgreSQL-compatible with strong global distribution features.

Architecture Comparison

TiDB's Architecture

TiDB separates compute (TiDB servers) from storage (TiKV). TiKV is a distributed key-value store using Raft consensus for replication. The unique addition is TiFlash, a columnar storage engine that maintains a real-time replicated copy of data for analytical queries. This lets you run OLTP and OLAP workloads on the same cluster without ETL.

YugabyteDB's Architecture

YugabyteDB uses a two-layer architecture: a query layer (YSQL for PostgreSQL, YCQL for Cassandra) and DocDB, a distributed document store. DocDB shards data into tablets, each replicated via Raft. YugabyteDB supports tablespace-level geo-partitioning, letting you pin data to specific regions for compliance and latency optimization.

HTAP: TiDB's Differentiator

TiDB's TiFlash engine is its standout feature. It maintains a columnar replica of your transactional data in real-time using Raft learners. Analytical queries automatically route to TiFlash while transactional queries hit TiKV. This eliminates the need for separate analytics infrastructure.

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Global Distribution: YugabyteDB's Strength

YugabyteDB's geo-partitioning lets you control where specific rows live geographically. Combined with its default serializable isolation, this makes it well-suited for globally distributed applications with data residency requirements.

The Bottom Line

Choose TiDB when you need MySQL compatibility with real-time HTAP analytics. Choose YugabyteDB when you need PostgreSQL compatibility with strong global distribution and serializable isolation. Both are excellent choices for horizontally scaling relational workloads.