Database Theory

From International Center for Computational Logic

Database Theory

Course with SWS 4/2/0 (lecture/exercise/practical) in SS 2022

Databases are a key technology in computer science that brings together fascinating theoretical topics and highly relevant practical applications. The goal of this lecture is to give an extended introduction to this interesting field, with a special focus on database query languages, their expressive power, and computational complexity. The lecture will introduce the relational data model, and then discuss theoretical and practical aspects of a variety of query languages:

  • first-order logic as a query language and the relational algebra
  • conjunctive queries and their unions
  • navigational queries: path queries
  • Datalog and its relatives
  • query answering under database dependencies

The lecture focuses on core principles that apply to many types of databases alike (relational, graph-based, semantic web). Some important query answering algorithms are presented, too, but otherwise, the details of database implementation and administration are not covered.

Prerequisites

Undergraduate-level knowledge of predicate logic, regular languages, and algorithmic and computational complexity is required. The lecture will connect with other topics in the Computer Science and Computational Logic curriculum, such as relational databases, logic programming, and Semantic Web technologies – familiarity with these topics is not required to follow the lecture.

Schedule and Location

  • The weekly lecture sessions will take place on Mondays from 09:20 to 10:50 in room APB E007 and Tuesdays from 09:20 to 10:50 in room APB E005.
  • The weekly exercise session will take place on Tuesdays from 14:50 to 16:20 in room APB E005.
  • The first exercise session will be on Tuesday, 2022-04-12.

Examinations

For the oral exams, we have blocked two dates this term:

  • Thursday, 2022-07-21 (fully booked)
  • Tuesday, 2022-08-02

As usual, you should book a date with our secretary after you have officially enrolled in your respective examination office/system.

Legacy

This course has first been taught at TU Dresden by Prof. Dr. Markus Krötzsch in the form of the 2015 lecture Foundations of Databases and Query Languages, the 2018 lecture Database Theory, and the 2019 lecture Database Theory. The plan for this year's course will be somewhat similar.

The structure of some of the lectures of this course is inspired by the course Theory of Data and Knowledge Bases in the version given by Georg Gottlob and Thomas Lukasiewicz at the University of Oxford.

The main reference textbook for the lecture is:

  • Serge Abiteboul, Richard Hull, Victor Vianu: Foundations of Databases. Addison-Wesley. 1994.
The book is available for free from its webpage, but there are also copies in the library.

Further texts might be consulted for background information and additional details:

  • Michael Sipser: Introduction to the Theory of Computation. 2005
Accessible introduction to complexity theory that covers all topics of computational complexity that the lecture touches upon.
  • Evgeny Dantsin, Thomas Eiter, Georg Gottlob, Andrei Voronkov: Complexity and expressive power of logic programming. ACM Computing Surveys, 33:3, pp 374-425, 2001.
Covers all Datalog complexity results mentioned in the lecture. Available at http://dx.doi.org/10.1145/502807.502810 (may require access from within a university network)
  • additional references will be added in the course of the lecture

Subscribe to events of this course (icalendar)

Lecture Introduction/Relational Data Model DS2, April 4, 2022 in APB E007 File
Lecture First-Order Queries (part 1) DS2, April 5, 2022 in APB E005 File
Lecture First-Order Queries (part 2) DS2, April 11, 2022 in APB E007
Lecture Complexity of Query Answering DS2, April 12, 2022 in APB E005 File
Exercise 1. Relational Algebra DS5, April 12, 2022 in APB E005 File 1 File 2
Lecture Complexity of FO Query Answering (1) DS2, April 19, 2022 in APB E005 File
Exercise 2. First-Order Queries DS5, April 19, 2022 in APB E005 File 1 File 2
Lecture Complexity of FO Query Answering (2) DS2, April 25, 2022 in APB E007 File
Lecture Conjunctive Queries DS2, April 26, 2022 in APB E005 File
Exercise 3. Complexity of First-Order Queries DS5, April 26, 2022 in APB E005 File 1 File 2
Lecture Tree-Like Conjunctive Queries (1) DS2, May 2, 2022 in APB E007 File
Lecture Tree-Like Conjunctive Queries (2) DS2, May 3, 2022 in APB E005 File
Exercise 4. Conjunctive Queries, CSP, and Hypergraphs DS5, May 3, 2022 in APB E005 File 1 File 2
Lecture Query Optimisation DS2, May 9, 2022 in APB E007 File
Lecture Conjunctive Query Optimisation DS2, May 10, 2022 in APB E005 File
Exercise 5. Tree Width and Hypertree Width DS5, May 10, 2022 in APB E005 File 1 File 2
Lecture Query Expressiveness (Part 1) DS2, May 16, 2022 in APB E007 File
Lecture Query Expressiveness (Part 2) DS2, May 17, 2022 in APB E005
Exercise 6. Trakhtenbrot's Theorem DS5, May 17, 2022 in APB E005 File 1 File 2
Lecture Introduction to Datalog DS2, May 23, 2022 in APB E007 File
Lecture Datalog Complexity DS2, May 24, 2022 in APB E005 File
Exercise 7. FO Query Expressivity DS5, May 24, 2022 in APB E005 File 1 File 2
Lecture Datalog Evaluation (1) DS2, May 30, 2022 in APB E007 File
Lecture Datalog Evaluation (2) DS2, May 31, 2022 in APB E005 File
Exercise 8. Datalog DS5, May 31, 2022 in APB E005 File 1 File 2
No session No Lecture: Pentecost DS2, June 6, 2022 in APB E005
No session No Lecture: Pentecost DS2, June 7, 2022 in APB E005
No session No Exercise: Pentecost DS5, June 7, 2022 in APB E005
Lecture Graph Databases and Path Queries DS2, June 13, 2022 in APB E007 File
Lecture Graph Databases and Path Queries (continued) DS2, June 14, 2022 in APB E005
Exercise 9. Semi-Positive Datalog DS5, June 14, 2022 in APB E005 File 1 File 2
Lecture Dependencies DS2, June 20, 2022 in APB E007 File
Lecture The Chase DS2, June 21, 2022 in APB E005 File
Exercise 10. Datalog Evaluation DS5, June 21, 2022 in APB E005 File 1 File 2
Lecture The Chase (continued; termination and acyclicity) DS2, June 27, 2022 in APB E007
Lecture Query Answering Beyond Acyclic TGDs DS2, June 28, 2022 in APB E005 File
Exercise 11. Graph Databases and Path Queries DS5, June 28, 2022 in APB E005 File 1 File 2
Lecture Query Answering Beyond Acyclic TGDs (continued) DS2, July 4, 2022 in APB E007
Lecture Outlook/Summary DS2, July 5, 2022 in APB E005 File
Exercise 12. Dependencies DS5, July 5, 2022 in APB E005 File 1 File 2
Lecture Consultation (time for your questions) DS2, July 11, 2022 in APB E007
No session No lecture DS2, July 12, 2022 in APB E005
Consultation Consultation (time for your questions) DS5, July 12, 2022 in APB E005


Calendar