CockroachDB vs DuckDB: What are the differences?

Introduction

CockroachDB and DuckDB are two popular database management systems with distinct features and use cases. In this comparison, we will highlight the key differences between these two databases.

1. Scalability: CockroachDB is designed to be highly scalable, offering horizontal scaling capabilities that allow it to handle large volumes of data and high traffic loads. It uses a distributed architecture with automatic data sharding, which ensures that data is evenly spread across multiple nodes. On the other hand, DuckDB is primarily built for single-node deployments and does not provide native support for horizontal scaling. It is optimized for fast analytical queries on smaller datasets.

2. Data Consistency Model: CockroachDB follows a strong consistency model, where data is always up-to-date and consistent across all replicas, ensuring that transactions are ACID-compliant. It utilizes a distributed consensus protocol called Raft to maintain consistency. In contrast, DuckDB, being an analytical database, relaxes consistency guarantees to provide faster query performance. It uses a MVCC (Multi-Version Concurrency Control) approach, allowing non-blocking reads while writes are ongoing.

3. Query Execution: CockroachDB supports distributed SQL execution, allowing queries to be parallelized and executed across multiple nodes. It provides query optimization features like cost-based query planning and indexing for efficient query processing. DuckDB, on the other hand, focuses on single-node query execution and optimization. It leverages vectorized query execution techniques and columnar storage to deliver fast analytical query performance on a single machine.

4. Data Types and SQL Dialect: CockroachDB supports a wide range of SQL data types, including structured, semi-structured, and unstructured data. It offers standard SQL syntax, as well as extensions for distributed SQL functionalities. DuckDB supports a subset of SQL data types, primarily focused on analytical workloads. Its SQL dialect is compatible with SQLite, providing compatibility with existing applications that use SQLite databases.

5. Storage Format: CockroachDB uses a hybrid storage format called RocksDB, which combines an LSM-tree (Log-Structured Merge Tree) for efficient write operations and an SSTable (Sorted String Table) for fast reads. This combination provides a good balance between write performance and read efficiency. DuckDB, being an analytical database, uses a column-oriented storage format. It organizes data by columns, allowing for efficient column-wise compression and query processing.

6. Community and Ecosystem: CockroachDB has a large and active community, with regular updates, bug fixes, and contributions from a diverse set of developers. It is backed by a company called Cockroach Labs, which provides enterprise support and additional services. DuckDB is a relatively new open-source project but has gained some traction in the analytics community. It is actively maintained by a smaller team of developers but has a growing ecosystem of tools and libraries around it.

In Summary, CockroachDB is a distributed database with strong consistency, scalability, and distributed query execution capabilities, while DuckDB is a single-node analytical database optimized for fast query performance on smaller datasets.