In Database Query Languages
Further information: Hierarchical and recursive queries in SQLSince the 1980s Oracle Database has implemented a proprietary SQL extension CONNECT BY... START WITH that allows the computation of a transitive closure as part of a declarative query. The SQL 3 (1999) standard added a more general WITH RECURSIVE construct also allowing transitive closures to be computed inside the query processor; as of 2011 the latter is implemented in IBM DB2, Microsoft SQL Server, and PostgreSQL, although not in MySQL (Benedikt and Senellart 2011:189).
Datalog also implements transitive closure computations (Silberschatz et al. 2010:C.3.6).
Read more about this topic: Transitive Closure
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