On solving efficiently the view selection problem under bag and bag-set semantics
作者:
Highlights:
• Query subexpressions do not always suffice for finding an optimal solution.
• Lgviews and subexpression views suffice for solving the bag version of the problem.
• d-Lgviews and subexpression views suffice for solving the bag-set version of the problem.
• Path-viewsets can be used to solve the bag version of the problem for path-queries.
• We prove significant conditions that useful viewsets satisfy under bag-set semantics.
摘要
Highlights•Query subexpressions do not always suffice for finding an optimal solution.•Lgviews and subexpression views suffice for solving the bag version of the problem.•d-Lgviews and subexpression views suffice for solving the bag-set version of the problem.•Path-viewsets can be used to solve the bag version of the problem for path-queries.•We prove significant conditions that useful viewsets satisfy under bag-set semantics.
论文关键词:View selection,Query rewriting,Bag semantics,Bag-set semantics
论文评审过程:Received 29 August 2012, Revised 12 December 2013, Accepted 8 January 2014, Available online 18 January 2014.
论文官网地址:https://doi.org/10.1016/j.is.2014.01.002