While not necessarily relevant when working with AutoCAD data, it’s very common for people to want to make use of adjacent database systems when developing AutoCAD applications.
For just this reason I’ve been meaning to post something on LINQ (and, in due course, PLINQ), but for now I recommend checking out this guest post from Joel Karr over on Jeremy Tammik’s The Building Coder.
Thanks for the tip, Jeremy! :-)