Toad for Oracle 9.5 and Toad for Data Analysis 1.1.0.328 both will install the same QExplain2.dll file under c:\Program Files\Common Files\Quest Shared folder. However, they have different versions. Toad's version is 6.0.5.1016 and TDA's version is 6.0.5.1019.
What is the difference and are they designed to be backwards compatible?
We've confirmed that the library is designed to be backwards compatible. The changes that were made all pertain to Unicode support and build 1019 should be backwards compatible with build 1016.
QExplain is a common component that displays execution (explain) plans for a product. This component provides a generic interface to support almost any database that has an execution (explain) plan. This component can be used with Oracle, SQL Server and DB2. The QExplain component also provides some rudimentary comparison functionality.