Query Optimization


Query optimization is addressed shortly in Database Systems, this lecture looks at a broader topic of optimization techniques. It concentrates on the central issues like join ordering and access path selections, but gives an overview of the whole query processing machinery. The main goals of the lecture are twofold: First, to learn different optimization techniques, which are also relevant in other areas. And second, to get an understanding how queries are processed and why queries are fast or slow.


  • Lecture: Mondays, 10:00 - 11:30 am in 02.11.018, prerecorded videos will be made available on moodle
  • Exercise: Mondays, 11:30 am - 1:00 pm in 02.11.018 or online on BBB, recordings of the BBB meetings will be made available on moodle


Unnesting Arbitrary Queries


Exercise sessions:

Exercise sessions will be made available on moodle


Exercise sheets will be distributed through moodle

You can work on exercises in teams of two students. Specify names of both participants when submitting

see gitlab and mattermost


  • J.D. Ullman. Database and Knowledge Base Systems. Computer Science Press, 1989.
  • T. Özsu and J. Blakeley. Modern Database Systems. Addison Wesley, 1995.
  • H. Garcia-Molina and J.D. Ullman and J. Widom. Database System Implementation. Prentice Hall, 1999.
  • P. Gassner, G. Lohman, and K. Schiefer. Query optimization in the IBM DB2 family. IEEE Data Engineering Bulletin, 16:4 18, Dec. 1993.
  • S. Chaudhuri. An Overview of Query Optimization in Relational Systems. PODS, 1998
  • G. Moerkotte. Building Query Compilers. (draft)