From Wide to Tall: A Proc SQL Approach to Transposing
Brandon Crosser · 2014
In many Extract, Transform, and Load (ETL) situations a large scale conversion is needed from a “wide” table structure to a “tall” table structure. This often occurs in transformation from a denormalized to normalized architecture. This paper presents techniques to gain efficiency in doing such loading with particular attention to reading and writing between SQL Server database tables. The techniques described within ensure that the process is table-driven and extensible with minimal code edits. A contrast of the technique with a PROC TRANSPOSE approach will be presented.