Tips on how to choose the correct data types

by Willen L
In this article the author focuses on the importance of proper data types in order to maintain data quality. He gives us some general tips and rules to follow to ensure the correct type is chosen. First, if the data is numeric, favor SMALLINT, INTEGER, OR DECIMAL Data types. Second, if the data is a character, use CHAR or VARCHAR data types. Third, if the data is date and time, use DATE, TIME, or TIMESTAMP data types. Lastly, if the data is a multimedia, use GRAPHIC, VARGRAPHIC, BLOB, or DBCLOB data types. These rules seem simple enough but he states that it is a widespread problem that people are using improper data types. The most common ones he encountered were using CHAR type on date data and using CHAR type on numerical data. Choosing the wrong data type may slow down the system and in general it is best to assign correct data type that best matches the values in the domain to improve overall data quality.

This article relates to our lectures as it talks about choosing the correct data types and to improve the speed and quality of the system. I think these rules are simple to follow and are good tips for us when we decide what data types need to be used in our design.

Mullins, C. (2007 August). Data Quality Starts with Proper Data Type. Craigsmullins. Retrieved Feb 06, 2012, from

4 thoughts on “Tips on how to choose the correct data types”

  1. This article is simple enough to understand and agree with. It’s amazing that improper data types are being used too often. Hopefully the next generation of workers can be the one to minimize the misuse. Thanks for the heads up!

  2. Basics are important, because they lay the foundation upon which you stand. And it’s good for me to read this article clarifying data types. Because it seems I will need the use of it now and in the future.

  3. When I took this course this information had me confused. Now that I am done with the course I can only suggest you guys really understand what the article is saying and really dig into the basics, they will come very handy when doing projects.

  4. Quite interesting that these variable mistakes have been made but this article seems to display the information quite clearly. It’s nice to know the mistakes ahead of time so that we won’t make them. Bringing it down to the basics is what we need and I’m glad you were about to find this article.

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