Databases, Cartography, and Geographic Information - A Primer of GIS: Fundamental Geographic and Cartographic Concepts - page 129

Examples for symbols used in classifying
roads in the United States.
table uses abbreviations (Rd., St., Ln., Ave.) or fails to use initial capitals. In
most cases the database software will not relate the two tables because at the
database's level of analysis (e.g., ASCII code) the street designations “Road”
and “Rd.” are different and unrelated.
Data Types
Database representation in most relational databases is restricted to a limited
number of data formats. The terms used here have other analogous terms,
some of which are indicated.
Integer: Whole numbers (1, 2, 3, 4,) are stored as integers.
Floating-point: Numbers with decimals (1.1, 2.4, 5.4,) are stored as floating
point numbers.
Character string, fixed, or variable length: Also called “text,” character
strings can be usually stored only in fixed-length fields. In some cases
the database software provides variable-length fields. If a word or text is
longer than the fixed length of the field, the characters after that place
will not be stored.
Examples of proper field length (top);
too short field length (middle); too long field length
(bottom).