Ordered sharing: A new lock primitive for database systems

Divyakant Agrawal, Amr El Abbadi

Research output: Contribution to journalArticle

2 Citations (Scopus)


We propose a new lock primitive called ordered sharing that allows increased concurrency in database systems. A generalized two phase locking protocol is developed that may employ locks with the standard shared and non-shared relationships as well as the proposed ordered shared relationships between locks. The paper then addresses the reliability and performance issues of the proposed protocol. We show that ordered sharing results in a set of protocols that are optimal in both their reliability and concurrency aspects. A simulation study demonstrates that ordered sharing results in improved performance in database systems. The general applicability of the new primitive is further demonstrated by using it in several representative database environments.

Original languageEnglish
Pages (from-to)361-392
Number of pages32
JournalInformation Systems
Issue number5
Publication statusPublished - 1 Jul 1995
Externally publishedYes



  • Concurrency Control
  • Database Recovery
  • Transaction Processing

ASJC Scopus subject areas

  • Software
  • Information Systems
  • Hardware and Architecture
  • Management Information Systems
  • Management of Technology and Innovation

Cite this

Agrawal, D., & El Abbadi, A. (1995). Ordered sharing: A new lock primitive for database systems. Information Systems, 20(5), 361-392.