I don't like the view option. Firstly, this is larger overhead than just getting the data directly from the table. Secondly, the ETL process should not govern the design of the warehouse based on updates. I always define the alternate key by way of a constraint or unique index for the table. Updating one column or two columns is of little consequence in the bigger picture. Alternatively, you could use computed column to manage the IsLatest column; by checking the latest effective date indicates if the field is the latest. Data Warehouses are all about performance for Cubes, Data Mining, and Queries. The use of views in this manor to me undermines this matter. The use of indiexes to enhance performance becomes a very much more complicated issue with views. For me this is a developer solution without looking at DBA issues on this matter. Placement of indexes on views has its own implications and starts to complicate the whole matter.
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