Disagree. It's mostly a question of whether the ORM was designed as a "least-common denominator of common operations supported by some RDBMSs" (which is clearly

Disagree. It's mostly a question of whether the ORM was designed as a "least-common denominator of common operations supported by some RDBMSs" (which is clearly the case for the Django ORM) or as an abstraction of SQL concepts (i.e. a form of relational algebra). The former category generally fares poorly with complex queries or structures; the latter exceeds at them.