When you create your table, you must indicate what type
of data each column will store. By thinking carefully about the nature
of the data you are going to be managing, you can set your tables
up in a way that will give you optimal query performance, minimize
physical storage requirements, and provide you with specialized capabilities
for manipulating different kinds of data, such as arithmetic operations
for numeric data, or comparing date or time values to one another.
Figure 1
shows the data types that are supported by Db2® databases. Figure 1. Built-in data types
When you declare your database columns all of these data types are available for you to
choose from. In addition to the built-in types, you can also create your own
user-defined data types that are based on the built-in types. For example, if you might
choose to represent an employee with name, job title, job level, hire date and salary attributes
with a user-defined structured type that incorporates VARCHAR (name, job title),
SMALLINT (job level), DATE (hire date) and DECIMAL (salary) data.
