The Benefits of Extract, Transform and Load (ETL)
ETL Tools
There are a number of commercial and open source ETL tools available to assist in any ETL process. Some of the prominent ones are:
- Business Objects Data Integrator
- Informatica PowerCenter
- IBM InfoSphere DataStage
- Oracle Warehouse Builder / Data Integrator
- Microsoft SQL Server Integration Services
- Pentaho Data Integration (Open Source)
- Jasper ETL (Open Source)
These tools provide a number of functions to facilitate the ETL workflow. The variety of source data types are handled automatically. A transformation engine makes it easy to create reusable scripts to handle the data mapping. Scheduling and error handling are also built in.
It is particularly advantageous to use an ETL tool in the following situations:
- When there are many source systems to be integrated
- When source systems are in different formats
- When this process needs to be run repeatedly (e.g. daily, hourly, real time)
- To take advantage of pre-built warehouses/marts. Many of these exist for popular platforms such as PeopleSoft, SAP, JD Edwards.
There are also times where the overhead and cost of setting up an ETL tool might not make sense. In these situations some combination of stored procedures, custom coding and off the shelf packages may make more sense. Scenarios of this type include:
- One time conversion of data
- A limited number of source systems that share key identifiers
