1. In a computing environment, a computer-implemented method performed at least in part on at least one processor for returning data to complete at least part of an augmentation task, comprising: receiving a query as input in the form of a query table including one or more entity names in a first query column and zero or more entity attributes in a second query column, accessing relationship-based data corresponding to relationships between a plurality of relational tables, the relationship-based data mined offline from at least one corpus and preprocessed offline into a plurality of indexes, and using the relationship-based data to: identify a direct relationship between the query table and a first relational table of the plurality of relational tables, identify an indirect relationship between the query table and a second relational table of the plurality of relational tables, identify a first score representing a first match between the query table and the first relational table, identify a second score representing a second match between the first relational table and the second relational table, and determine one or more entity attributes to return to augment the query table and complete the at least part of the augmentation task, the one or more entity attributes determined based at least partially on the first score and the second score.