Title
Processing top-k join queries
Abstract
We consider the problem of efficiently finding the top-k answers for join queries over web-accessible databases. Classical algorithms for finding top-k answers use branch-and-bound techniques to avoid computing scores of all candidates in identifying the top-k answers. To be able to apply such techniques, it is critical to efficiently compute (lower and upper) bounds and expected scores of candidate answers in an incremental fashion during the evaluation. In this paper, we describe novel techniques for these problems. The first contribution of this paper is a method to efficiently compute bounds for the score of a query result when tuples in tables from the "FROM" clause are discovered incrementally, through either sorted or random access. Our second contribution is an algorithm that, given a set of partially evaluated candidate answers, determines a good order in which to access the tables to minimize wasted efforts in the computation of top-k answers. We evaluate our algorithms on a variety of queries and data sets and demonstrate the significant benefits they provide.
Year
DOI
Venue
2010
10.14778/1920841.1920951
PVLDB
Keywords
Field
DocType
novel technique,branch-and-bound technique,incremental fashion,expected score,classical algorithm,random access,top-k answer,candidate answer,good order
Data mining,Data set,Tuple,Computer science,Database,Random access,Computation
Journal
Volume
Issue
ISSN
3
1-2
2150-8097
Citations 
PageRank 
References 
10
0.49
15
Authors
5
Name
Order
Citations
PageRank
Minji Wu12069.84
Laure Berti-Équille2120.85
Amélie Marian3128077.92
Cecilia M. Procopiuc467840.37
Divesh Srivastava589841191.22