TiDB vs YugabyteDB: What are the differences?

Introduction

TiDB and YugabyteDB are both distributed SQL databases that provide scalability, high availability, and compatibility with different data models. However, they differ in several key aspects, which are outlined below:

1. Storage Layer: In TiDB, the storage layer is powered by TiKV, a distributed key-value store. This allows for horizontal scalability and high availability. On the other hand, YugabyteDB uses the YB-TServer layer, which is a distributed transactional key-value store. This provides a similar level of scalability and availability but with added support for distributed transactions.

2. Consistency Model: TiDB follows a strict serializable consistency model, ensuring that all transactions see a consistent state of the database. On the other hand, YugabyteDB supports both serializable and snapshot isolation levels, providing more flexibility in choosing the desired consistency requirement for a specific use case.

3. SQL Compatibility: TiDB is fully compatible with MySQL, which means that existing MySQL applications can seamlessly migrate to TiDB without the need for significant code changes. YugabyteDB, on the other hand, provides PostgreSQL compatibility, allowing applications built on PostgreSQL to work with YugabyteDB without major modifications.

4. Sharding Approach: TiDB uses a range-based sharding approach, where data is distributed across different partitions based on a defined range. In contrast, YugabyteDB adopts a hash-based sharding approach, where data is hashed and distributed across different nodes based on the hash value. This difference impacts the way data is distributed and how queries are executed.

5. Multi-Cloud Support: YugabyteDB offers native multi-cloud support, allowing users to deploy clusters across multiple cloud providers or on-premises data centers. This provides flexibility and redundancy options for distributed applications. On the other hand, while TiDB can be deployed on multiple cloud providers, it does not provide native multi-cloud support out-of-the-box.

6. Data Replication: TiDB follows a synchronous replication model by default, where data is replicated across different nodes in real-time. This ensures strong consistency but may introduce some latency. In contrast, YugabyteDB supports both synchronous and asynchronous replication, giving users the option to choose between strong consistency or lower latency.

In summary, TiDB and YugabyteDB differ in the choice of storage layer, consistency model, SQL compatibility, sharding approach, multi-cloud support, and data replication options. These differences offer users the ability to select the database that best aligns with their specific requirements and use cases.