Dynamic Management Views and Functions are used to retrieve information about SQL Server internals. The Dynamic Management Objects first, introduced in SQL Server 2005. The subsequent releases added many new DMVs while some got changed. Sometime new columns can be added and column names can be changed in new versions. So it is recommended to use SELECT * whenever you want to get internal information using DMVs. This is especially important when developing production monitoring code. So that the possibility of breaking your code is less with new SQL Server versions.