It falls into the 'right tool for the right job'
Financials, order entry, etc need to be exact. By comparison many of the largist data set operations (such as business/trend analysis) can easily afford to loose a small amount of data (often the noise in the original data can be larger than such data loss).
If you use a highly structured data system for non rigid data, you probably are using too many resources.
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-- FORTRAN manual for Xerox Computers --