I want to create a table to store user ratings of items for collaborative filtering algorithms. So far my table looks like this:
IID | UID | Rating i.e.
item ID |user id |rating.
From collaborative algorithm examples the tables rather look like:
Item ID | Rating U1 | Rating U2 | ... | Rating Un
This means i would have to alter (extend) the table every time a new user signs up. Alternatively i have to create a new table for each user. Both does not seem to be very efficient solution. Can anyone point me into the right direction?