Field specifications are important for these reasons:
a. They help establish and enforce field-level integrity.
b. They help enhance overall data integrity.
c. They compel you to acquire a complete understanding of the nature and purpose of the data in the database.
d. They constitute the “data dictionary” of the database.
Field-level integrity warrants the following:
a. The identity and purpose of a field is clear, and all of the tables in which it appears are properly identified.
b. Field definitions are consistent throughout the database.
c. The values of a field are consistent and valid.
d. The types of modifications, comparisons, and operations that can be applied to the values in the field are clearly identified.
The three ...