“…Top-k query processing has received much attention in a variety of settings such as similarity search on multimedia data [7,24,29,30,45,46], ranked retrieval on text and semistructured documents in digital libraries and on the Web [3,6,36,40,48,52,55], network and stream monitoring [4,14] collaborative recommendation and preference queries on ecommerce product catalogs [17,31,42,56], and ranking of SQL-style query results on structured data sources in general [1,11,18]. Among the ample work on top-k query processing, the TA family of algorithms for monotonic score aggregation [25,30,46] stands out as an extremely efficient and highly versatile method.…”