Personally, I would try attacking this problem from a different direction. I'm assuming that if Sally is John's friend then John is also Sally's friend. So, let's suppose that Sally (key S1) reads the book Great Expectations (key E1) and has friends John (key J1) and Mike (key M1). I would add a table that looks something like:
userKey tag bookKey numFriends friendsList and add an index on userKey, tag, bookKey, numFriends So, when Sally indicates she has read Great Expectations (E1). I would add (or modify if entries for these users/book combinations already exist) two entries to this table (one entry for each of her friends), so it would look like: userKey tag bookKey numFriends friendsList --------------------------------------------------------------- J1 historical+drama E1 1 Sally M1 historical+drama M1 1 Sally Now let's say Ken (K1) is a friend of John's but not Mike's and he reads Great Expections, so table would look like: userKey tag bookKey numFriends friendsList --------------------------------------------------------------- J1 historical+drama E1 2 S1,K1 M1 historical+drama M1 1 S1 And finally, let's say Betty (B1) is a friend of Johns and reads Moby Dick (D1) so table would be: userKey tag bookKey numFriends friendsList --------------------------------------------------------------- J1 historical+drama E1 2 S1,K1 J1 historical+drama D1 1 B1 M1 historical+drama M1 1 S1 Now, querying this table should be fast and efficient along with sorted properly. Well, this is the way I'd do it. Hope it helps. Steve -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
