Open Source and the Data Lakehouse: Apache Iceberg and Project Nessie

thumbnail
Open Source and the Data Lakehouse: Apache Iceberg and Project Nessie

Oberhofen village on the lake Thun, Switzerland

The data lakehouse concept presents a harmonious fusion of the strengths of both data lakes and data warehouses.

Written By
thumbnail
Alex Merced
Alex Merced
Nov 2, 2023

The emergence of the data lakehouse concept has yielded transformative solutions that effectively address the challenges of traditional data lakes and data warehouses. While offering scalability and cost-efficiency advantages, data lakes often lack inherent structure, complicating data organization and query performance. On the other hand, data warehouses excel in structured data storage and retrieval efficiency but need to catch up in accommodating the diverse and ever-expanding nature of modern data types.

In the face of these obstacles, the data lakehouse has become a harmonizing force. It unites the appealing attributes of data lakes and data warehouses, promising a harmonious blend of flexibility, scalability, structured data management, and analytical prowess.

However, many solutions for creating a data lakehouse come with an unexpected marriage to a particular vendor or tool. This is precisely where the collaborative efforts of open-source initiatives like Apache Iceberg and Project Nessie offer an alternative. By seamlessly integrating with these projects, data lakes transform remarkably into dynamic data lakehouses, overcoming the limitations of traditional paradigms. The integrations result in an agile, versatile, and robust data management solution that combines the strengths of both worlds without any long-run obligation to any vendor.

Apache Iceberg: Unlocking the Potential of Data Lakehouses

Apache Iceberg is an open-source project introducing a new table format for managing data on a data lake. This format enables tools to interact with data stored in the lake like traditional database tables. It introduces a metadata layer between your tools and your data files. This metadata layer allows tools to scan the data on a data lake more intelligently. It’s a revolutionary approach enabling several features that transform data lakes into efficient data lakehouses. These include:

ACID Transactions: Iceberg supports ACID (Atomicity, Consistency, Isolation, Durability) transactions, ensuring data integrity and consistency. This is a critical feature for scenarios where multiple processes must read and write data simultaneously.

Schema Evolution: Iceberg allows for seamless schema evolution. As data changes, the table schema can evolve without requiring massive transformations or downtime. This is essential for maintaining data integrity and minimizing disruptions.

Partition Evolution: With Iceberg, you can efficiently manage partitioning schemes. This feature, unique to Apache Iceberg, allows you to change your partitioning scheme without having to rewrite all your data.

Time Travel: You can query the table in its current state and any previous state, thanks to Apache Iceberg’s snapshot isolation.

Hidden Partitioning: Iceberg introduces the concept of hidden partitioning, which provides the benefits of partitioning without exposing the complexities to end users. By defining unique partitioning patterns as transformed values of a column instead of creating a derived column, engines can partition by month, day, or hour by a truncated value or a set number of buckets—without introducing complexity in how the end user queries the table.

See also: Are Data Lakehouses the Panacea We’ve Been Waiting For, Or Is There Something Better?

Advertisement

Project Nessie: Catalog Management for Data Lakehouses

Project Nessie complements Apache Iceberg by providing a versioned and transactional catalog for data lakehouses. Think of it as a “Git for metadata.” It allows you to manage and track changes to the metadata of tables stored in Iceberg format. Each Nessie commit is a list of keys representing tables, views, namespaces, and more, each with metadata attached. Across Nessie, you can track commits and audit and manage the changes to not just a single table but to your entire catalog. This brings a range of benefits:

Isolating Ingestion: Nessie enables the isolation of data ingestion. You can create a branch of your catalog, ingest your data, run data quality checks, and then publish the data through a merge into your default branch when done.

Zero Copy Environment Generation: With Nessie, you can create isolated environments for different analytical tasks without duplicating data. Each environment references the same underlying data while having its own metadata snapshot. So, changes in a particular environment are isolated to that environment without duplicating the shared data.

Disaster Recovery: By capturing the entire history of catalog changes, Nessie aids in disaster recovery scenarios. You can rollback your catalog to historical commits with ease to recover from any disaster.

Multi-Table Transactions: Nessie extends Iceberg’s transactions to the catalog level, allowing multiple table changes to be grouped together in a single transaction. This ensures consistency across multiple table modifications.

Reproducibility: By tagging catalog commits, you can quickly run queries on the catalog as it was at a particular point in time.

See also: Real-time Data and Database Design: Why You Should Sweat the Small Stuff

Advertisement

Iceberg and Nessie for Real-Time Data

Apache Iceberg and Project Nessie substantially benefit the management of real-time data within a data lakehouse architecture context. Ensuring data integrity and consistency is paramount when dealing with real-time data streams. Apache Iceberg’s support for ACID transactions and schema evolution provides a solid foundation for managing real-time data updates seamlessly. This means that as real-time data flows in, Iceberg maintains the transactional integrity of updates while accommodating changes to the data structure without disruption.

Additionally, Project Nessie’s versioned and transactional catalog capabilities can be pivotal in tracking and managing changes to real-time data tables. This facilitates efficient change management in dynamic data environments, allowing organizations to confidently introduce updates to real-time data pipelines while maintaining a comprehensive audit trail. By leveraging these open-source tools, organizations can streamline real-time data integration into their data lakehouse, ensuring accurate and up-to-date insights for timely decision-making.

Advertisement

Empowering Your Data Lakehouse

While data lakes provide scalability and cost-effectiveness, the lack of inherent structure hampers efficient data organization and querying. Conversely, data warehouses excel in structured data management but struggle with the diversity of modern data types. The data lakehouse concept presents a harmonious fusion of the strengths of both paradigms, promising scalability, structured data management, and analytical prowess.

However, many solutions inadvertently tether users to specific vendors or tools. Here, open-source collaborations such as Apache Iceberg and Project Nessie prove invaluable.

Seamlessly integrated into these projects, data lakes undergo a metamorphosis into dynamic data lakehouses, transcending the constraints of conventional models and providing an agile, versatile, and powerful data management solution that combines the best of both worlds without any lasting vendor obligations. This convergence of innovation and adaptability shapes the future of data management, empowering organizations to harness their data’s potential without compromise.

thumbnail
Alex Merced

Alex Merced is the co-author of “Apache Iceberg: The Definitive Guide” and Head of Developer Relations at Dremio, providers of the leading, unified lakehouse platform for self-service analytics and AI. With experience as a developer and instructor, his professional journey includes roles at GenEd Systems, Crossfield Digital, CampusGuard, and General Assembly. He co-authored "Apache Iceberg: The Definitive Guide," published by O'Reilly, and has spoken at notable events such as Data Day Texas and Data Council. Follow Alex on LinkedIn, X, or Dremio at LinkedIn.

Recommended for you...

How Data Hydration Enables Scalable and Trusted AI
Peter Harris
Feb 12, 2026
The Observability Gap AI Exposed
Tim Gasper
Jan 21, 2026
Data Immediacy’s Next Step
Smart Talk Episode 9: Apache Iceberg and Streaming Data Architectures

Featured Resources from Cloud Data Insights

Agentic AI and the Death of SaaS
The Business Case for a Unified Semantic Layer
Alex Merced
Mar 12, 2026
Domain-Specific LLMs: How to Make AI Useful for Your Business
Hardik Parikh
Mar 11, 2026
Engineering the Agentic Enterprise: Building Smarter, Adaptive, Autonomous Systems
Varun Goswami
Mar 10, 2026
RT Insights Logo

Analysis and market insights on real-time analytics including Big Data, the IoT, and cognitive computing. Business use cases and technologies are discussed.

Property of TechnologyAdvice. © 2026 TechnologyAdvice. All Rights Reserved

Advertiser Disclosure: Some of the products that appear on this site are from companies from which TechnologyAdvice receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. TechnologyAdvice does not include all companies or all types of products available in the marketplace.