A data warehouse is a central repository for data which will be used for reporting and analytics. Data comes into the data warehouse from [[Online Transaction Processing|transactional systems]], relational databases, or [[Data Lake|other sources]] usually on a regular cadence. Business analysts, data engineers, data scientists, and decision makers then access the data through [[Business Intelligence|business intelligence]] tools, [[SQL]] clients, and other analytics applications. Because the primary use cases for a data warehouse revolve around analytics, they typically use an [[Online Analytical Processing|OLAP]] technology for performance. ## Data Warehouse Advantages - Consolidate data from multiple data sources into one "source of truth" - Optimized for read access which makes generating reports faster than using a source transaction system for reporting - Store and analyze large amounts of historical data ## Data Warehouse Disadvantages - A significant investment of time and resources to properly build - Not designed for ingesting data in real-time (although they can typically handle near real-time) ## When to use a Data Warehouse Data warehouses are made for complex queries on large datasets. You should consider a data warehouse if you're looking to keep your historical data separate from current transactions for performance reasons. ## Popular Data Warehouses - [[Tools/Databases/Amazon Redshift|Amazon Redshift]] - [[Azure Synapse Analytics]] - [[Google BigQuery]] - [[Microsoft SQL Server]] - [[Snowflake]] ## Data Warehouse Benchmarks - 1 TB: [2020 - Redshift, Snowflake, Presto and BigQuery](https://fivetran.com/blog/warehouse-benchmark) - 30 TB: [2019 - Redshift, Azure SQL Data Warehouse, BigQuery, Snowflake](https://gigaom.com/report/cloud-data-warehouse-performance-testing/) ![[Learning Resources#Data Warehousing Learning Resources]] %% wiki footer: Please don't edit anything below this line %% ## This note in GitHub <span class="git-footer">[Edit In GitHub](https://github.dev/data-engineering-community/data-engineering-wiki/blob/main/Concepts/Data%20Architecture/Data%20Warehouse.md "git-hub-edit-note") | [Copy this note](https://raw.githubusercontent.com/data-engineering-community/data-engineering-wiki/main/Concepts/Data%20Architecture/Data%20Warehouse.md "git-hub-copy-note")</span> <span class="git-footer">Was this page helpful? [👍](https://tally.so/r/mOaxjk?rating=Yes&url=https://dataengineering.wiki/Concepts/Data%20Architecture/Data%20Warehouse) or [👎](https://tally.so/r/mOaxjk?rating=No&url=https://dataengineering.wiki/Concepts/Data%20Architecture/Data%20Warehouse)</span>