Functional-join processing

R. Braumandl, J. Claussen, A. Kemper, D. Kossmann

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Inter-object references are one of the key concepts of object-relational and object-oriented database systems. In this work, we investigate alternative techniques to implement inter-object references and make the best use of them in query processing, i.e., in evaluating functional joins. We will give a comprehensive overview and performance evaluation of all known techniques for simple (single-valued) as well as multi-valued functional joins. Furthermore, we will describe special order-preserving functional-join techniques that are particularly attractive for decision support queries that require ordered results. While most of the presentation of this paper is focused on object-relational and object-oriented database systems, some of the results can also be applied to plain relational databases because index nested-loop joins along key/foreign-key relationships, as they are frequently found in relational databases, are just one particular way to execute a functional join.

Original languageEnglish
Pages (from-to)156-177
Number of pages22
JournalVLDB Journal
Issue number3-4
StatePublished - Feb 2000
Externally publishedYes


  • Functional join
  • Logical OID
  • Object identifier
  • Order-preserving join
  • Physical OID
  • Pointer join
  • Query processing


Dive into the research topics of 'Functional-join processing'. Together they form a unique fingerprint.

Cite this