[CarCdr]

Your code would take the threadid of a hit, and then retrieve all the rows from the secondary table based on threadid.

A hit is when you are displaying a thread from the "special" forum. For such a display, you will want to retrieve the other information not in the thread table. That is when you would do the lookup in your one to 0..N relationship table.

If you use a flat table for the download information, you would not need to do this as you could use JOIN's to get the information when the thread table retrieval is performed.