Reorganizing queries with grouping
Rui Okura, Yukiyoshi Kameyama · 2020
Language-integrated query has attracted much attention from researchers and engineers. It enables one to write a database query with high-level abstractions, which makes it possible to compose, iterate, and reuse queries. An important issue in language-integrated query is the N+1 query problem, and Cheney et al. proposed a program-transformation approach to solve it for a core language of Microsoft’s LINQ. In our previous work, we extended their language to grouping (GROUP BY in SQL) and aggregate functions, and showed that any term can be transformed to a single SQL query. It still has a problem in that the resulting queries may be unnecessarily large and inefficient.