TABLE OF CONTENTS Populating, or loading data into a database system often requires copying (migrating) data from various disparate sources or legacy databases. In these cases, it is usually necessary to perform some sort of data reformatting, modification, or transforming to ensure that all the data in the new, combined database system are internally consistent. This chapter introduces the basic concepts of data reformatting, presents selected case histories, and outlines suggested potential solutions for the most common data reformatting problems.
Even with the integration and standardization of modern data management and intepretive applications, there will inevitably be cases where data need to be reformatted for another application. In some instances, the reformatting process is simple and automatic, but complex reformatting problems require careful planning and standardization.
One of the purposes of reformatting data is to standardize the database contents. Smooth, efficient, accurate database operation requires that all contents (data) conform to specified standards for format, style, and content.
Data reformatting is commonly necessary to convert a data element from one format to another. Consistent field formats are necessary to make data accessible and compatible throughout the database. For example, consider a dataset being loaded from a legacy system to an existing database. In the legacy dataset, dates have been stored as text fields, but in the existing database they need to be stored in a date/time format. The legacy data therefore need to be converted from text to dates so that all values in that...
