October 22, 2014 \ Ananth TM Data Staging Area What is the Data Staging Area? The data staging area sits between the data source(s) and the data target(s). This is where data sits prior to being scrubbed and transformed into a data warehouse / data mart. Having one common area makes it easier for subsequent data processing / integration. Here data gains its “intelligence”, as logic is applied to transform the data from a transactional nature to an analytical nature. This area is also where data cleansing happens. The ETL design phase is often the most time-consuming phase in a data warehousing project, and an ETL tool is often used in this area. Sometimes also referred to as staging layer. Why Data Staging Area? Staging areas can be designed to provide many benefits, but the primary motivations for their use are to increase efficiency of ETL processes, ensure data integrity and support data quality operations. Due to varying business cycles, data processing cycles, hardware and network resource limitations and geographical factors, it is not feasible to extract all the data from all Operational databases at exactly the same time. Not all businesses require a Data Warehouse Staging Area. Most businesses use ETL to copy data directly from operational databases into the Data Warehouse. Staging Area The functions of the staging area include the following: Consolidation Alignment Minimize contention Change detection Data cleansing Data Archival troubleshooting More details on Data Staging Area… Data staging areas are often transient in nature, with their contents being erased prior to running an ETL process or immediately following successful completion of an ETL process. Staging areas can be implemented in the form of tables in relational databases, text-based flat files (or XML files) stored in file systems or proprietary formatted binary files stored in file systems. Staging area architectures range in complexity from a set of simple relational tables in a target database to self-contained database instances or file systems.