The seminal work of Selinger et al. A. Union and set difference b. Left outer join 14.16 Give an example of an expression defining a materialized view and two situations (sets of statistics for the input relations and the differentials) such that incremental view maintenance is better than recomputation in one situation, and recomputation is better in the other situation. 14.15 Describe how to incrementally maintain the results of the following operations, on both insertions and deletions. A. Union and set difference b. Left outer join 14.16 Give an example of an expression defining a materialized view and two situations (sets of statistics for the input relations and the differentials) such that incremental view maintenance is better than recomputation in one situation, and recomputation is better in the other situation.