What is a data lake?
A data lake is a centralized storage platform that ingests large volumes of structured, semi-structured, and unstructured data in its raw form and makes it available for analytics, machine learning, and big data applications. Unlike traditional databases, a data lake does not impose a fixed structure when data is ingested. Instead, the schema is defined when the data is queried. Bissantz helps companies design and leverage data landscapes that include data lakes.
| Characteristic | Details |
| Category | Data architecture / big data / data storage |
| Purpose | Centralized storage and delivery of large volumes of heterogeneous data for analytics and AI |
| Typical applications | Business intelligence, data science, machine learning, reporting, real-time analytics |
| Related terms | Data warehouse, data lakehouse, big data, ETL, data governance, OLAP |
| Benefits | Flexible data storage, fewer data silos, cost efficiency, future readiness |
At a glance
Stores structured, semi-structured, and unstructured data without requiring a predefined structure.
Combines the flexibility of a data lake with the analytical capabilities of a data warehouse.
Provides a foundation for AI applications and data-driven business management.
Data lake definition
A data lake is a centralized storage platform that enables organizations to store and manage large volumes of data in a wide range of formats. Raw data is ingested and stored in its native format. This means that both structured data, such as database tables, and unstructured data, such as text documents, videos, or social media content, can be stored in a data lake.
The stored data can then be used for big data analytics, machine learning, real-time analytics, reporting, and other modern applications. Data lakes provide a comprehensive and flexible view of an organization’s data, creating a strong foundation for data-driven decision-making.
What types of data can a data lake store?
A data lake can store structured, unstructured, and semi-structured data:
| Data type | Examples |
| Structured data | Tabular datasets from relational databases, numerical information |
| Semi-structured data | JSON, XML, and CSV files |
| Unstructured data | Text documents, PDFs, audio and video files, images, social media content, emails |
The ability to store data in different formats makes data lakes a valuable resource for organizations that need to work with broad and diverse datasets for analytics and innovative applications.
Is a data lake a database?
A data lake is not a traditional database. It is a flexible storage platform designed to ingest large volumes of raw data in its original format. While databases are specifically structured to store particular types of data in tables and support real-time queries, a data lake serves as a central repository for a wide range of data types, from structured to unstructured data.
Why are data lakes useful? – benefits of data lakes
Data lakes give organizations a powerful way to store, manage, and make large volumes of data available for analytics. Key benefits include:
Flexible data storage
Cost efficiency through cloud-based scalability
Fewer data silos
Integration with AI and machine learning
Data integration
Future readiness through the preservation of raw data
Fast data availability for data scientists and analysts
Data lake vs. data warehouse: What is the difference?
A data warehouse typically relies on relational database management systems and organizes data from multiple sources in a central repository using predefined schemas. Data warehouses are optimized for structured data.
A data lake, by contrast, can also store data from non-relational databases in its raw format without imposing a fixed schema, making it more flexible. Data lakes are often preferred when working with unstructured and semi-structured data.
| Characteristic | Data lake | Data warehouse |
| Data structure | Raw, unstructured, schema-on-read | Structured, schema-on-write |
| Data types | Structured, semi-structured, unstructured | Primarily structured data |
| Flexibility | Very high | Limited |
| Primary use | Exploration, AI, machine learning, big data | Reporting, BI, standardized analytics |
How does a data lake work? – data lake architecture
A data lake architecture consists of several layers:
Data ingestion layer
Storage layer
Processing layer – for example, using Apache Hadoop or Spark
Metadata layer – including data catalogs and metadata
Access layer – for example, for data visualization with tools such as DeltaMaster
What is a data lakehouse?
A data lakehouse is a modern data architecture that combines the flexibility of a data lake with the structured analytical capabilities of a data warehouse. It incorporates features such as ACID transactions, data versioning, and schema enforcement, providing:
- Better data management without switching between systems
- Higher data quality and data integrity through structured governance on a flexible data foundation
A data lakehouse helps eliminate data silos and makes it possible to manage and analyze structured and unstructured data within a single, consistent architecture.
Data lakes and Bissantz
A data lake provides the technical foundation for making large volumes of diverse data centrally available. But to generate real value, it is crucial to structure, integrate, govern, and prepare that data for specific business requirements.
Bissantz helps companies develop the right data architecture and integration strategy — from analyzing existing data sources and systems to defining appropriate data models and metrics and designing efficient analytics and reporting processes. The focus is not on technology for its own sake, but on determining what information the organization actually needs for planning, controlling, and management — and how that information can be delivered reliably.
Another key focus is turning technical data assets into business-ready information. Bissantz helps organizations harmonize data sources, define metrics consistently, and prepare data so that business teams and management can derive reliable insights from it. Tools such as DeltaMaster can be used for analytics, planning, and reporting.
Practical example
An international company wants to bring its sales, finance, and production data together in a data lake. Although the data already exists in various systems, differences in data structures, metric definitions, and data quality make consistent analysis difficult.
As part of a consulting project, Bissantz first analyzes the existing data sources and the business requirements of the participating departments. Relevant metrics — such as revenue, contribution margin, and order intake — are then defined consistently, and the required data flows and structures are designed. This creates a robust architecture that brings operational data sources and analytical requirements together.
The benefits quickly become apparent: Instead of manually reconciling different versions of the data, business teams can work with consistent and traceable information. Analyses and reports can be created faster, and deviations can be evaluated consistently across departments and locations. The data lake thus becomes more than a data repository — it becomes a solid foundation for effective business management
FAQ – frequently asked questions
A data lake is like a giant digital reservoir: all kinds of data can flow into it — whether tables, text, images, or videos — and the data is only structured when it is needed. Unlike a database, which structures data as it is stored, a data lake initially keeps data in its raw form.
Schema-on-read means that the structure of the data is defined when it is queried rather than when it is ingested. This provides maximum flexibility: the same data can be interpreted differently for different analytical purposes without having to transform it in advance.
A data lake makes sense when an organization generates large volumes of heterogeneous data, plans to use AI or machine learning, or needs to break down existing data silos. For purely structured operational reporting, a data warehouse may be sufficient.
A data lakehouse combines the flexibility of a data lake with the structure and analytical capabilities of a data warehouse on a single platform. It adds features such as ACID transactions, schema enforcement, and data versioning to the data lake, potentially eliminating the need for a separate data warehouse in many scenarios.
DeltaMaster integrates the data required for analysis, calculates metrics using consistent business logic, and presents them in dashboards and reports. This turns raw data in the data lake into decision-relevant information for controlling and management.
Summary
A data lake provides a flexible foundation for modern data architectures: it stores all types of data in their raw form, helps eliminate data silos, and creates a foundation for AI, machine learning, and big data analytics. Combined with a data warehouse — or implemented as a data lakehouse — it can form a powerful, future-ready data infrastructure. With DeltaMaster, Bissantz makes data stored in the data lake usable for controlling and Business Intelligence: structured, visualized, and focused on better decisions.
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