Abstract
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 | English |
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| Pages | 98-107 |
| Number of pages | 10 |
| DOIs | |
| State | Published - 2005 |
| Externally published | Yes |
| 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
| Conference | Twenty-Fourth ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, PODS 2005 |
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| Country/Territory | United States |
| City | Baltimore, MD |
| Period | 13/06/05 → 15/06/05 |
Bibliographical note
Funding Information:* Corresponding author. E-mail addresses: [email protected] (S. Cohen), [email protected] (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).