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  2. Join (SQL) - Wikipedia

    en.wikipedia.org/wiki/Join_(SQL)

    The joined table retains each row—even if no other matching row exists. Outer joins subdivide further into left outer joins, right outer joins, and full outer joins, depending on which table's rows are retained: left, right, or both (in this case left and right refer to the two sides of the JOIN keyword).

  3. Set operations (SQL) - Wikipedia

    en.wikipedia.org/wiki/Set_operations_(SQL)

    The discussion of full outer joins also has an example that uses ... Designing a data flow that loads a warehouse table; Oracle 11g documentation for UNION (ALL ...

  4. Relational algebra - Wikipedia

    en.wikipedia.org/wiki/Relational_algebra

    The right outer join ( ) behaves almost identically to the left outer join, but the roles of the tables are switched. The right outer join of relations R and S is written as R S. [e] The result of the right outer join is the set of all combinations of tuples in R and S that are equal on their common attribute names, in addition to tuples in S ...

  5. Quick Objects - Wikipedia

    en.wikipedia.org/wiki/Quick_Objects

    Support for Complex Joins and Keys All types of complex joins and keys are supported including Left, Right, and Outer joins. Keys with multiple columns are supported as well. Database Independent Eliminates the need to write database specific code and the same code base can be used against any of the supported databases without a recompile.

  6. Comparison of relational database management systems - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_relational...

    Oracle: Yes 11: Cluster Tables ... Outer joins Inner selects Merge joins Blobs and clobs Common table expressions Windowing functions Parallel query System-versioned ...

  7. Null (SQL) - Wikipedia

    en.wikipedia.org/wiki/Null_(SQL)

    SQL outer joins, including left outer joins, right outer joins, and full outer joins, automatically produce Nulls as placeholders for missing values in related tables. For left outer joins, for instance, Nulls are produced in place of rows missing from the table appearing on the right-hand side of the LEFT OUTER JOIN operator. The following ...

  8. Correlated subquery - Wikipedia

    en.wikipedia.org/wiki/Correlated_subquery

    In a SQL database query, a correlated subquery (also known as a synchronized subquery) is a subquery (a query nested inside another query) that uses values from the outer query. This can have major impact on performance because the correlated subquery might get recomputed every time for each row of the outer query is processed.

  9. Block nested loop - Wikipedia

    en.wikipedia.org/wiki/Block_nested_loop

    A block-nested loop (BNL) is an algorithm used to join two relations in a relational database. [1]This algorithm [2] is a variation of the simple nested loop join and joins two relations and (the "outer" and "inner" join operands, respectively).