There are two implementations of the DataSource interface that are included with the native JDBC driver. These DataSource implementations should be considered deprecated. While you can still use them, they are not enhanced with future improvements; for example, robust connection and statement pooling are not added to these implementations. These implementations exist until you adopt the UDBDataSource interface and its related functions.
The DB2DataSource was an early implementation of the DataSource interface and does not comply with the complete specification (that is, it predates the specification). DB2DataSource exists today only to allow WebSphere® users to migrate to current releases and should not be used otherwise.
The DB2StdDataSource is the revised version of the DB2DataSource implementation that became specification-compliant once the JDBC optional package specification became final. The new version was provided to not break code already written on the DB2DataSource version.
If you have written applications that make use of these DataSource implementations, migrating to the UDBDataSource is a trivial task as all the old properties are supported. It is recommended that you migrate to UDBDataSource to gain the functionality of the new UDBDataSource classes.