Optimizing top-k selection queries over multimedia repositories

Surajit Chaudhuri, Luis Gravano, Amélie Marian

Research output: Contribution to journalArticlepeer-review

92 Scopus citations


Repositories of multimedia objects having multiple types of attributes (e.g., image, text) are becoming increasingly common. A query on these attributes will typically request not just a set of objects, as in the traditional relational query model (filtering), but also a grade of match associated with each object, which indicates how well the object matches the selection condition (ranking). Furthermore, unlike in the relational model, users may just want the k top-ranked objects for their selection queries for a relatively small k. In addition to the differences in the query model, another peculiarity of multimedia repositories is that they may allow access to the attributes of each object only through indexes. In this paper, we investigate how to optimize the processing of top-k selection queries over multimedia repositories. The access characteristics of the repositories and the above query model lead to novel issues in query optimization. In particular, the choice of the indexes used to search the repository strongly influences the cost of processing the filtering condition. We define an execution space that is search-minimal, i.e., the set of indexes searched is minimal. Although the general problem of picking an optimal plan in the search-minimal execution space is NP-hard, we present an efficient algorithm that solves the problem optimally with respect to our cost model and execution space when the predicates in the query are independent. We also show that the problem of optimizing top-k selection queries can be viewed, in many cases, as that of evaluating more traditional selection conditions. Thus, both problems can be viewed together as an extended filtering problem to which techniques of query processing and optimization may be adapted.

Original languageEnglish (US)
Pages (from-to)992-1009
Number of pages18
JournalIEEE Transactions on Knowledge and Data Engineering
Issue number8
StatePublished - Aug 2004
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Information Systems
  • Computer Science Applications
  • Computational Theory and Mathematics


  • Information retrieval
  • Information search
  • Multimedia databases
  • Top-k query processing


Dive into the research topics of 'Optimizing top-k selection queries over multimedia repositories'. Together they form a unique fingerprint.

Cite this