Real-world datasets are hardly ever clean and pristine. They commonly include blanks, nulls, duplicates, errors, malformed text, mismatched data types, and a host of other problems that degrade data quality. No matter how much data one might have, a small amount of high quality data is more beneficial than a large amount of garbage data. All decisions derived from data will be better with higher quality data.
In this section we will introduce some of the methods and techniques that Spark offers for dealing with “dirty data”. The term dirty data means data that needs to be improved so the decisions made from the data will be more accurate. The topic of dirty data and how to deal with it is a very broad topic with a lot of things to consider. This chapter intends to introduce the problem, show Spark techniques, and educate the user on the effects of “fixing” dirty data.
It’s interesting to see what’s available in Spark and how you can take advantage of it.