Code taking long time to execute

[ppr (Peter Preuss)]

Have a look here for optimization analysis steps

LINQ query running for long hours

Let us introduce the next changes [grafik] we are creating lists with the concatenated strings from dtold, dtnew and creating a dictionary of only the items common in both lists dtNewSet.asEnumerable.Select(Function (x) String.Join(“#”, arrColSet.Select(Function (k) x(k).toString.ToLower.Trim))).Distinct().toList dtOldSet.asEnumerable.Select(Function (x) String.Join(“#”, arrColSet.Select(Function (k) x(k).toString.ToLower.Trim))).Distinct().toList ListDT1.Intersect(ListDT2).ToDictionary(Fun…