Performance Improvement on Recursive CTE

One big finding for today is that when using recursive CTE, the leaner the recursive member table is the better. This basically means getting only the fields that are necessary for the recursive CTE. Any other fields such as Tile, Description are to be pulled after the recursive CTE. It also means doing the recursive as early as possible in the big overall query.

This practise brought a SQL query running time from 30 seconds to 1 second. Huge, huge difference!