Last monday we released the new DataCleaner 2.0 and one of the major new features in it is the ability to transform and filter your data using the tool. Previously the common answer for someone asking about transformation in DataCleaner has been to tell them that "there are already good tools for this available elsewhere, so use them". So why did we choose to focus on data processing in DataCleaner 2.0? And what are the capabilities of DataCleaner in terms of transformations? Is DataCleaner over time going to evolve into a full-fledged ETL tool? I'll try to answer these questions.
All your data quality functions in one place
The obvious answer is that we want to provide more data quality functionality and that transformations is something that a lot of people need. While doing data profiling it is often needed to do data adjustments, eg. to tokenize values, extract certain information, filter which rows gets profiled etc. You can also do all this also by applying an ETL tool or maybe even by creating database VIEWs. The problem with such an approach is that it will eventually get in your way because you're trying to get 2-3 independent tools to work nicely together, instead of just having these functions available where you need them.
Transformations for the DQ domain
Possibly even more important is that the transformations that you want to employ in Data Quality analysis are typically quite different than those that come out-of-the-box in database scripts and ETL tools. Such tools are typically quite generic and will provide general purpose tokenizers etc., but will typically lack transformations pertaining to the DQ-domain, such as date mask matchers, dictionary lookups and synonym replacements, standardization of email adresses, names and URL's.
When you do pre-processing in separate tools, you also need to persist your transformed datasets. In Data Quality analysis this is just a waste of resources and provides poor performance. If you need to perform transformations, apply filtering etc. for the purpose of analysis, profiling and exploring your data it is much more feasible to just perform these transformations when needed in stead of storing them up front. This also allows for a much more free user experience where you can actually experiment with your data and you analysis in stead of having to overthink it.
Is DataCleaner's validator gone? No, it's just filtering with added output handling!
DataCleaner 1.x was known to have a strict separation between the activities "profile" and "validate". Since this separation is gone in 2.0, one might ask, "Is DataCleaner's validator gone? I can only see analysis jobs!". But the answer is no, we just consider validation as a type of analysis (thus, analysis is a broader term, comprising both profiling, validation and more). You can easily perform all the validation operations of DataCleaner 1.x, but the approach is a bit different because you basically apply filters in stead of "validators". There is even an example of this in the "Introduction to analyzing, cleansing and filtering data" webcast, available on DataCleaner's website.