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Data & Analytics

What is Data Lake?

Quick answer

A central repository that stores large volumes of raw data in its original format until it is needed for analysis.

Data Lake, explained

A data lake accepts structured data like database tables, semi-structured data like JSON logs, and unstructured data like images or documents, usually on inexpensive cloud object storage. Data is stored first and structured later, an approach sometimes called schema-on-read.

This flexibility is useful for data science and machine learning, where analysts may not know in advance which data will prove valuable. The risk is that, without governance, cataloguing, and quality controls, a data lake can become a data swamp that nobody trusts. A related architecture, the lakehouse, combines the low-cost storage of a lake with the management features and query performance of a data warehouse.

Related terms

Big Data

Datasets so large, fast-moving, or varied that traditional tools struggle to store and process them efficiently.

Data Lakehouse

A data architecture that combines the low-cost, flexible storage of a data lake with the structure and query performance of a data warehouse.

Data Mesh

An approach to data architecture that gives business domains ownership of their own data, shared as products across the organization.

Data Warehouse

A system that stores cleaned, structured data from many sources, optimized for reporting and business analysis.

ETL

Extract, Transform, Load: a process that pulls data from sources, cleans and reshapes it, and loads it into a destination such as a data warehouse.

Object Storage

A cloud storage method that keeps data as individual objects with metadata in a flat structure, suited to large amounts of unstructured files.

Zettabyte

A unit of digital information equal to one sextillion (10 to the power of 21) bytes, or one billion terabytes.

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