In case of categorical attributes (e.g., Gender, Job, and City), we allocate one cell per attribute. For continuous domain attributes (e.g., age and salary), we divide the space into N parts, where parts have almost equal number of ratings. More sophisticated techniques can be used to divide the space. Yet, we opt for a simple division here as a proof of concept for RECATHON functionality. (2) RecModel Building, where the RecModel table for each cell C in G is built by running the specified recommender algorithm in the CREATE RECOMMENDER statement on the set of users U whose attributes correspond to the subdomain covered by C. For instance, in case of ItemCosCF recommendation algorithm, we scan the ratings table and run a nested loop algorithm over all items to calculate the cosine similarity score between every item pair in each cell C using equation 1. After the initialization procedure terminates, a pointer to the newly created grid structure G is added to the RecIndex field corresponding to the appropriate recommender entry in RecCatalog.