AWS currently offers two options for effectively storing, managing, and analyzing vast amounts of data. The two centralized data repository solutions are Data Lake and Data Warehouse. 

The subsequent sections compare and contrast Data Lakes and Data Warehouses across eight different dimensions to assist readers in making an informed decision. 

Data LakeData Warehouse
DataStores data that may or may not be curated.Stores highly-curated data that serves as the central version of the truth. 
SchemaSchema-on-read i.e. the schema is written at the time of analysisSchema-on-write i.e. the schema is defined prior to the implementation
ScalabilityHighly scalable. Can handle large volumes of structured and unstructured data with ease.Scalable. However, may require more resources and planning for handling large amounts of data.
InsightsSuitable for raw data exploration and big data analytics. May require additional data processing to gain insights.Designed for generating business insights through structured, processed data.
CostsLower-cost storage in Amazon S3. However, the cost per query can be higher for larger volumes of data.Higher-cost storage in Amazon Redshift, AWS’s data warehouse. However, the cost per query is lower.
AdaptabilityHighly adaptable and versatile, able to store and process new data types without changes to the schema. Cost-effective when adding data science processes.Less adaptable to unstructured or rapidly changing data types.
PerformanceCan easily handle large volumes of data. Could be slower for structured data queries when compared to a Data Warehouse.Optimized for high performance in querying structured data. Is less efficient when handling unstructured data.
MaintenanceLower maintenance as it does not require a predefined schema. However, may require more effort in data organization and management.Higher maintenance due to schema requirements. However,  structured data makes it easier to manage.

1. Dat

Data Lake – Data

A Data Lake on AWS is capable of ingesting both non-relational and relational data from multiple sources, such as IoT devices, websites, mobile apps, social media, and corporate applications. Providing a unified repository for storing diverse data formats, a data lake allows for the storage of raw and uncurated data. This flexibility enables organizations to capture and retain data in its original form, without immediate concern for data structure or specific use cases.

Data Warehouse – Data

A Data Warehouse primarily deals with relational data obtained from transactional systems, operational databases, and line of business (LOB) applications. It focuses on storing highly-curated data that serves as the central version of the truth for business intelligence and enhanced decision-making. Data within a Data Warehouse is typically structured and transformed to align with a predefined schema, ensuring consistency and accuracy in analysis.

2. Schema

Data Lake – Schema

A Data Lake adopts a schema-on-read approach. In a Data Lake, the schema is applied at the time of analysis or querying, rather than during the data ingestion phase. Users can define the schema and structure the data according to their specific analysis requirements. Schema-on-read provides agility and versatility in data exploration, as it allows for on-the-fly schema modifications and adaptations. However, a schema-on-read approach also means data quality checks and validation are performed during the analysis phase. This could potentially lead to delays in data availability for analysis.

Data Warehouse – Schema

A Data Warehouse follows a schema-on-write approach, where the schema is defined and applied to the data prior to its ingestion into the Data Warehouse. This approach requires upfront planning and consideration of the data structure to ensure data integrity and organization. The advantage of schema-on-write is that it allows for better data governance and control, enabling data validation and quality checks at the point of ingestion. However, any changes to the schema will require data reprocessing and could potentially impact the agility and speed of data analysis.

3. Scalability

Data Lake – Scalability

A Data Lake on AWS is highly scalable and can effortlessly handle large volumes of structured and unstructured data. Built on Amazon S3, a highly scalable object storage service, Data Lakes can accommodate data growth without any significant limitations.

Data Warehouse – Scalability

While a Data Warehouse on AWS is also scalable, it may require additional resources and planning to handle large amounts of data efficiently. Amazon Redshift, the data warehouse solution offered by AWS, allows users to scale their clusters up or down based on changing needs. However, compared to a Data Lake, scaling a Data Warehouse might involve more considerations, such as optimizing query performance and data distribution strategies.

4. Insights

Data Lake – Insights

A Data Lake is well-suited for raw data exploration and big data analytics. It provides a repository for storing a wide range of data types, including structured, semi-structured, and unstructured data. However, gaining insights from a Data Lake often requires additional data processing and transformation steps. Raw data exploration, data discovery, and data science processes can be conducted on the Data Lake to derive valuable insights.

Data Warehouse – Insights

A Data Warehouse is designed for the specific purpose of generating business insights through structured, processed data. It serves as a consolidated repository for clean, transformed, and curated data. A Data Warehouse is optimized for running complex queries on structured data models, enabling business intelligence and reporting functionalities.

5. Costs

Data Lake – Costs

A Data Lake offers cost advantages due to its utilization of Amazon S3. Storing data in S3 can be cost-effective when dealing with larger volumes of data. However, the cost per query can increase as the volume of data grows, especially if extensive processing and transformation are required before querying the data.

Data Warehouse – Costs

A Data Warehouse, like Amazon Redshift, incurs higher storage costs compared to Amazon S3. Redshift is a columnar storage-based data warehouse optimized for querying structured data efficiently. However, the cost per query in a Data Warehouse is typically lower compared to a Data Lake, especially for structured data queries that align with the optimized architecture of a Data Warehouse.

6. Adaptability

Data Lake – Adaptability

A Data Lake excels in adaptability and versatility. It allows you to store and process different data types, including structured, semi-structured, and unstructured data, without the need for predefining a schema. This flexibility makes a Data Lake well-suited for scenarios where data types evolve rapidly or where the schema is not fixed. It is also an ideal choice when incorporating data science processes and exploring new data sources.

Data Warehouse – Adaptability

While a Data Warehouse can handle structured data effectively, it is less adaptable to unstructured or rapidly changing data types. Data Warehouse architectures typically rely on predefined schemas to structure and organize data. As a result, accommodating new data types or modifying existing schemas may require more effort and planning.

7. Performance

Data Lake – Performance

Due to its scalable architecture, a Data Lake can handle large volumes of data efficiently. However, when it comes to structured data queries, a Data Lake might not perform as optimally as a Data Warehouse. Due to the nature of a Data Lake, which involves exploring and processing raw data, querying structured data may require additional processing steps. This could result in slightly slower performance compared to a Data Warehouse optimized for structured data.

Data Warehouse – Performance

A Data Warehouse, such as Amazon Redshift, is designed to provide high performance for querying structured data. It leverages columnar storage and parallel query execution to deliver fast results for complex queries. However, when dealing with unstructured data or performing raw data exploration, a Data Warehouse might not deliver the same level of efficiency as a Data Lake.

8. Maintenance

Data Lake – Maintenance

Maintaining a Data Lake generally requires less effort in regard to schemas. As mentioned earlier, a Data Lake allows for schema-on-read, meaning the data schema is determined during the data retrieval process. While this flexibility reduces schema-related maintenance, it can make the process of organizing and managing data within the Data Lake more difficult. AWS Glue, a fully managed extract, transform, and load (ETL) service, helps address this challenge by automating schema discovery and cataloging to ease the data organization process.

Data Warehouse – Maintenance

The predefined schema in a data warehouse enables easier data management and simplifies maintenance tasks. However, schema changes or modifications can require more involvement and careful planning. The structured nature of a Data Warehouse provides a more controlled environment for managing data, but it comes at the cost of increased maintenance efforts associated with schema maintenance.

Conclusion

Both Data Lake and Data Warehouse solutions offer distinct advantages and considerations for data analytics. A Data Lake provides scalability, adaptability, and cost advantages, making it suitable for raw data exploration and big data analytics. On the other hand, a Data Warehouse offers optimized performance, structured data insights, and simplified maintenance, albeit at a higher storage cost. 

Next Steps

Implementing a data lake or data warehouse on AWS can be a complex task, demanding expertise in data analytics workflows, architectural design, and AWS services. To ensure a successful implementation, partnering with an experienced AWS Partner like TrackIt is highly recommended. Track It has deep expertise in building comprehensive data solutions and can provide comprehensive guidance from initial planning to architecture design, implementation, and ongoing maintenance.

About TrackIt

TrackIt is an Amazon Web Services Advanced Tier Services Partner specializing in cloud management, consulting, and software development solutions based in Marina del Rey, CA. 

TrackIt specializes in Modern Software Development, DevOps, Infrastructure-As-Code, Serverless, CI/CD, and Containerization with specialized expertise in Media & Entertainment workflows, High-Performance Computing environments, and data storage.

In addition to providing cloud management, consulting, and modern software development services, TrackIt also provides an open-source AWS cost management tool that allows users to optimize their costs and resources on AWS.