in reply to Re: Store results by search term, not session ID
in thread Database searches with persistent results via CGI
Anyway, the gist of it was that you can use the table structure you suggested or serialize the whole result data structure into a blob column using Storable.
Also, make if your search criteria are in a hash make sure you sort them before you use them as the result key. Hashes can return their keys in a different order, even when the keys are identical.