VLDB 2021 Demo: Sound of Databases

	Authors
Name:	Professor Dr. rer. nat. habil. Sven Groppe	Rico Klinckenberg	Benjamin Warnke, M.Sc.
Affiliation:	University of Lübeck Institute of Information Systems (IFIS) Ratzeburger Allee 160 (Building 64 - 2nd Level) D-23538 Lübeck Germany
EMail:	groppe [a*t] ifis.uni-luebeck.de	rico.klinckenberg [a*t] gmx.net	benjamin.warnke [a*t] uni-luebeck.de
URL:	https://www.ifis.uni-luebeck.de/~groppe		https://www.ifis.uni-luebeck.de/index.php?id=warnke

@article{groppe2021sound,
  author    = {Sven Groppe and Rico Klinckenberg and Benjamin Warnke},
  title     = {Sound of Databases: Sonification of a Semantic Web Database Engine},
  journal   = {Proc. {VLDB} Endow.},
  volume    = {14},
  number    = {12},
  pages     = {2695--2698},
  year      = {2021},
  url       = {https://doi.org/10.14778/3476311.3476322}
}

Sonification is typically defined as the use of nonspeech audio to convey information [...] for the purposes of facilitating communication or interpretation. Sonifications map data to auditory dimensions and offer a new audible experience to their listeners. We propose a sonification of query processing paired with a corresponding visualization both integrated in a web application. In this demonstration we show that the sonification of different types of relational operators generates different sound patterns, which can be recognized and identified by listeners increasing their understanding of the operators' functionality and supports easy remembering of requirements like merge joins work on sorted input. Furthermore, new ways of analyzing query processing are possible with the sonification approach.

With our sonification demonstration of a database, we address a large spectrum of target audiences and discuss the benefits of our sonification for these audiences in the following paragraphs.

General Public

Sonification is a means to offer a multimedia show to the general public at events attracting more people. By offering sonification applications to be used by any persons, sonification of databases may help scientists to increase the interest in database technologies in a playful way. It may help for an easy understanding of database technologies offering an audio-visual presentation of the data processing.

Students

Computer science students may more easily learn and don't forget the learned facts about database algorithms especially if these can be recognized in the sonification. For example, the sonification of merge joins may result in an ascending scale remembering the student that the input of merge joins must be sorted.

Our purpose is not only to reach students of computer science or related subjects but also to reach students of foreign subjects to give them an access to the basics of databases. So our main focus are associations like: What happens with my query request? How is it processed? How do I request special data? Sonification shall help them to recognize regularities and differences of varying optimizations of requests audio-visually.

To make computer science and its mostly theoretical topics more interesting to students and pupils, multimedia applications are beneficial. In cases that school students can experiment and create unique and interesting solutions on their own, it drums up interest for usually monotonous topics. Even in computer science there should be possibilities to arrange those topics in an exciting way. With the support of visual and auditive attractions pupils should playfully and perhaps musically learn the basics to work with databases. The main focus is learning with fun, to discover the features of such applications on their own to get access to databases and computer science topics.

Teaching Staff

Our demo is beneficial to teaching staff no matter if they are teaching at universities, schools or provide seminars for employees. Our solution provides an easy access to a complex topic to any level of students and pupils. Therefore different adaptations will be needed depending on the teaching method: presentation of results or experimenting. So in the first case the teacher will be able to record single query requests or create problem depending sound mappings in advance.

Developers of Database Engines

Irregular patterns and anomalies in the sound of the sonification are a hint for errors in the code, such that a sonification of a database engine helps developers to identify these errors. Furthermore, patterns in the sound may help to analyze performance issues and may provide hints which code is worth to be and how this code should be optimized. Especially repeating sound patterns may be a hint for repeating calculations, which might be avoided improving the performance of the overall calculation. Scientists may also get ideas for efficient super operators replacing several simpler operators.

Visually Impaired

Experiments show that visually impaired can recognize the location of nodes in graphical data when using a proper mapping from the 3D location to auditory dimensions for sonification. The graphical data are the operator trees of query execution plans for our proposed sonification. Hence our proposed sonification helps the visually impaired to understand the database technologies, especially query processing and its algorithms, and to make them audibly tangible for these technologies.

Musicians/Artists

All interested persons including musicians and artists are invited to experiment with a new tool to create unique sounds. The possibility to assemble new rhythms and melodies out of a learning tool for a computer science topic is great. For this reason we offer the option to use different instruments and sounds at the same time.

The following video provides a short introduction into the usage of the sonification demonstration:

Start Sonification Demonstration

We describe the different used queries for our sonification demonstration. The used queries are presented with an increasing complexity and we motivate their use in the demonstration by discussing the demonstration purposes like learning effects of students.

Sonification of single operators

Experienced database developers and scientists may be asked for their guess what kind of relational operator is introduced in the sonification demonstration for the following queries. Novices to database technologies may be asked about their guess of the functionality of the considered query.

One Triple Pattern

The first query for the sonification demonstration is a simple query consisting only of one triple pattern. The listeners of the sonification hear an ascending scale getting to know that the solutions of triple patterns can be determined by accessing an index of pre-sorted data.

Start Sonification Demonstration

Filter

The second query adds a filter. Listeners of the sonification recognize that not all intermediate results are passing the filter operator playing the previous tone generated by the index scan with another instrument.

Start Sonification Demonstration

Merge Join

This query consists of a binary operator having two inputs and one output. Two index scan operators as well as the output of the merge join play with different instruments. Listeners notice that only if the two inputs of the index scan operators are the same, an output is generated.

Start Sonification Demonstration

Optional-Clause/Left Outer Join

This query contains an optional-clause, such that a left outer join occurs in the operator tree of the query execution plan. In comparison to the merge join, the input of the left index scan passes always the left outer join - even if it is not combined with the input of the right index scan.

Start Sonification Demonstration

Hash Join

This query consists of a merge join of two triple patterns and a succeeding hash join combining the result of the previous merge join with a triple pattern. The hash join is implemented as pipeline breaker by generating the output after reading the complete input of one operator.

Start Sonification Demonstration

Sonification of Complex Queries

In this section we describe the sonification of more complex queries allowing further analysis and generating a more complex ensemble of sound effects.

Recognizing Single Operators in Complex Queries

Listeners of sonifications of very complex queries may recognize single operators in the complex ensemble of different operators and their generated sounds during query processing.

Start Sonification Demonstration

Common Subexpressions

Queries consisting of the same subexpressions several times in the query generate a repeating sound during sonification, such that listeners may notice these common subexpressions.

Start Sonification Demonstration

Similar queries

The sonification of similar queries generates similar sound with some few differences (like passing other solutions in different filters), which might be recognized by the listeners of the sonification.

Start Sonification Demonstration

Queries generating inspiring Sounds

Some sonifications of complex queries may generate interesting regular patterns, which may inspire musicians and artists for new musical compositions.

Start Sonification Demonstration

Other Videos

Quiz

The slides are available here!