building a dimension from multiple sources

What is the best method for building a dimension from multiple sources?

For example, we have patient table and a language table. We want to build the type 2 dimension with data from both tables. What is the best approach when the language description changed and the patient data did not change? The patient table is large and we do not want to process all the records from the patient table every day. We want to process only the changed rows from the patient table and the changed rows from the language.

Exclude the language description from the process to Identify changes to the patients. After the load, update the language description in the dimension from the second source. I would add in a where statement to limit the updates to rows that actually had a different language desciptions (where d.Language_Desc <> S.Language_Desc). No sense updating rows with the exact same data.

Is there a way to implement a single step process?

Build a checksum, compare the incoming checksum to the dimensional checksum. If different, update.