An advanced data warehouse, also known as an enterprise data warehouse, serves as a data hub for business intelligence. It is a support system that stores data across the organization processes it, and enables it to be utilized for various business purposes, including reporting, business analysis, and dashboards. A data warehouse system stores structured data from multiple sources such as Online Transaction Processing (OLTP), Customer Relationship Management (CRM), and Enterprise Resource Planning (ERP).
Data warehouse architecture
Data warehouse architecture is typically divided into three categories:
Single-tier architecture: This type of architecture focuses on reducing the amount of data stored in order to remove data redundancy. This architecture is rarely used nowadays.
Two-tier architecture: In this type of architecture, two layers separate the physically available data warehouse sources. This type, however, does not support most end-users due to a lack of expanding capabilities. Moreover, network limitations and connectivity problems were also reported with this architecture.
Three-tier architecture: Conventional data warehouses were developed using three-tier architecture, and it continues to be the most widely used architecture for data warehouse modernization. It is divided into three tiers, bottom, middle, and top.
Bottom tier: This tier consists of the database of the data warehouse servers. The bottom tier is generally considered as a relational database system in which the data is filtered, modified, and loaded into the layer.
Middle tier: This layer embodies an OLAP (Online Analytical Processing) server that is actualized using MOLAP (Multidimensional OLAP) or ROLAP (Relational OLAP) model. For end-users, these tiers offer a preoccupied database view, along with functioning as the bridge between the user and the database.
Top tier: This tier act as the front-end client layer that consists of API and tools which enable you to connect to the warehouse and connect data. The top tiers may consist of reporting tools, query tools, managed query tools, data mining tools, and analysis tools.