Comparison illustration of a Data Lake (purple layered cylinder) against a Data Warehouse (purple house) on a blue background, asking 'What's the Difference?'

Guide to Data Lake vs. Data Warehouse

Data lakes store raw, diverse data for analysis, while data warehouses store structured data for reporting and BI. Learn about the key differences between data lakes and data warehouses.

6 key differences between data lakes and data warehouses

When deciding between a data lake vs a data warehouse (or perhaps both), it helps to compare their characteristics side by side. Below is a breakdown of their key differences.

Feature  Data Lake Data Warehouse
Data Type Stores raw, unstructured, and semi-structured data (e.g., IoT data, images). Stores processed, structured data (e.g., sales records, customer addresses).
Users Data scientists, engineers, and advanced analysts who want access to raw data. Business users and analysts who need quick, reliable access to reports.
Schema Design Schema on read—data is organized only when it’s used for analysis. Schema on write—data is cleaned and structured before entering.
Processing Supports batch and real-time processing. Primarily optimized for structured, batch processing.
Cost and Scalability Lower storage costs; scales easily for massive datasets. Higher costs due to processing and storage optimization.
Security and Governance Requires strong data governance to manage unstructured data access. Security is usually built in.
Table comparing Data Lakes and Data Warehouses across 6 key differences: Data Type, Users, Schema Design, Processing, Cost and Scalability, and Security and Governance.

Data lake vs. data warehouse FAQs

A data lake stores raw, unprocessed data, while a data warehouse organizes and processes data before storing it. Data lakes are flexible and ideal for unstructured or semi-structured data, such as IoT streams or social media posts. Data warehouses are optimized for fast querying of structured data, so they tend to be most useful for reporting and analytics.

Not entirely. Data lakes excel at storing large, diverse datasets but lack the structure and speed that warehouses provide for operational reporting and BI. Many businesses find that combining both systems offers the best results.

Data warehouses remain essential, but hybrid systems like data lakehouses and platforms like Data 360 are gaining traction. These solutions combine the flexibility of a data lake with the structure of a warehouse.

If your organization relies on unstructured data or needs to preserve information for machine learning and AI workflows, a data lake might be a better choice. It provides cost-effective storage and supports advanced analytics, which equips your data science teams with the tools they need.

Data warehouses are costlier because of the processing involved in cleaning and organizing data before storage. This upfront investment gives you more speed and accuracy during analysis. Data lakes, on the other hand, store raw data, which makes them less expensive to scale but requires a bit more effort to extract insights.