EVALUATION OF QUERY FOR DATA ITEM HAVING MULTIPLE REPRESENTATIONS IN GRAPH ON A SUB-QUERY BY SUB-QUERY BASIS UNTIL DATA ITEM HAS BEEN RETRIEVED

Sub-queries for a query are ordered. The query is for retrieving a data item of a data graph. The data graph stores representations of the data item. Each representation stores information represented by the data item in a different manner or way. Each sub-query corresponds to a different representation in which the data graph stores the data item. The sub-queries are ordered in an ordered list according to likelihood that evaluation thereof will yield an appropriate or selected representation of the data item that is correct for the query and that correctly answers the query. The sub-queries within the ordered list are evaluated on a sub-query by sub-query basis, until the data item has been retrieved.