The full disjunction is a variation of the join operator that maximally combines tuples from connected relations, while preserving all information in the relations. The full disjunction can be seen as a natural extension of the binary outerjoin operator to an arbitrary number of relations and is a useful operator for information integration. This paper presents the algorithm INCREMENTALFD for computing the full disjunction of a set of relations. INCREMENTALFD improves upon previous algorithms for computing the full disjunction in three ways. First, it has a lower total runtime when computing the full result and a lower runtime when computing only k tuples of the result, for any constant k. Second, for a natural class of ranking functions, INCREMENTALFD returns tuples in ranking order. Third, INCREMENTALFD can be adapted to have a block-based execution, instead of a tuple-based execution.
|Original language||American English|
|Number of pages||10|
|State||Published - 2005|
|Event||Twenty-Fourth ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, PODS 2005 - Baltimore, MD, United States|
Duration: 13 Jun 2005 → 15 Jun 2005
|Conference||Twenty-Fourth ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, PODS 2005|
|Period||13/06/05 → 15/06/05|
Bibliographical noteFunding Information:
* Corresponding author. E-mail addresses: firstname.lastname@example.org (S. Cohen), email@example.com (Y. Sagiv). URL: http://iew3.technion.ac.il/~sarac (S. Cohen). 1 The author was partially supported by Israel Science Foundation (Grant 1032/05). 2 The author was partially supported by Israel Science Foundation (Grant 893/05).