After you install the driver, you configure data sources to connect to the database. Data sources store the Information that the driver needs to connect to a database. The ODBC specification describes three types of data sources: user data sources, system data sources (not a valid type on Linux), and file data sources. On Windows, user and system data sources are stored in the registry of the local computer. The difference is that only a specific user can access user data sources, whereas any user of the machine can access system data sources. On Windows and Linux, file data sources, which are simply text files, can be stored locally or on a network computer, and are accessible to other machines.
The data source contains connection options that allow you to tune the driver for specific performance. If you want to use a data source but need to change some of its values, you can either modify the data source or override its values at connection time through a connection string.
If you choose to use a connection string, you must use specific connection string attributes. See "Connection Option Descriptions" for an alphabetical list of driver connection string attributes and their initial default values.
