Pitney Bowes MapInfo Professional - Manual (Page 42)

Emergency medical calls thematically shaded by type of call and time of call, with response zones shaded
by number of calls.
To understand MapInfo Professional, you need a basic understanding of database organization, in
particular, three fundamental concepts: record, field, index, and query.
ZIPCode Address FirstName LastName
12205 212 Hudson St Mark Fraser
12208 459 Yates St Eva Donaldson
12180 200 Broadway Kim Espinosa
12065 1 Redbird Ln Charles Smith
12077 53 Crescent Rd Elizabeth Chang
To understand the database concepts we are about to discuss, consider the table above.
Each row in the list contains information about one person. In database terms, each row is a record.
Each different box of information (Last Name, First Name, etc.) within a record is called a field. Fields
correspond to the columns so that the table shown above contains four different fields.
Database fields are ordered (first, second, third, fourth, etc.), and the basic convention is that the first
field displays as the first column in the database. The second field is in the column to the right of the
first, and so on to the last field, which is displayed in the right most column.
Since the data in a database is not usually in alphabetical order or postal code order or any other pattern
which would make it easy for the computer to find the information, the computer needs a way to organize
the information. A database uses an index to keep track of what information is where and what record
it is tied to. Without indices it would be tedious to find anything in a database with hundreds of records,
not to mention databases with thousands and tens of thousands of records.
A database index works on the same principle as a book index. A book index is an alphabetical list of
topics that appear in the book and the page number or address of the information. Database indices
work in a similar way, except that they generally work behind the scenes. You do not ever see them.
But the computer constructs them and allows you to use them in your work. An index allows the computer
to work with the records according to the order of items in the key field.
MapInfo Professional requires fields to be indexed in order to use the Find command. Indices are also
used to improve performance in SQL Select and joins.
MapInfo Professional 12.5 42
Data - Where MapInfo Professional Begins