Editing Transitive closure (section)

== In database query languages ==
{{further|Hierarchical and recursive queries in SQL}}
Since the 1980s [[Oracle Database]] has implemented a proprietary [[SQL]] extension <code>CONNECT BY... START WITH</code> that allows the computation of a transitive closure as part of a declarative query. The [[SQL 3]] (1999) standard added a more general <code>WITH RECURSIVE</code> 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]], [[Oracle Database|Oracle]], [[PostgreSQL]], and [[MySQL]] (v8.0+). [[SQLite]] released support for this in 2014.

[[Datalog]] also implements transitive closure computations.<ref>(Silberschatz et al. 2010:C.3.6)</ref>

[[MariaDB]] implements Recursive Common Table Expressions, which can be used to compute transitive closures. This feature was introduced in release 10.2.2 of April 2016.<ref>{{cite web| title=Recursive Common Table Expressions Overview| url=https://mariadb.com/kb/en/recursive-common-table-expressions-overview/| publisher=mariadb.com}}</ref>