a free-form database query language for mobile phones
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A Free-Form Database Query Language for Mobile Phones. Kevin Pheasey. Presentation Overview. Introduction Related Work How the language was implemented Main concepts of query language Test. Current Limits. - PowerPoint PPT PresentationTRANSCRIPT
Kevin Pheasey
Introduction Related Work How the language was implemented Main concepts of query language Test
Majority of the database querying systems developed for mobile access are for use on PDAs
The systems only provide minimal querying capabilities
Mostly pre-determined queries limits the use
Support for different types of queries as well as unplanned queries
Use Minimal Resources Be easy to use given the restricted screen
size
Current query languages are restricted by the domain of the application◦ Hung and Zhang telemedicine system◦ Kobayashi and Paungma transportation system
Systems cannot be put on a mobile phone because of a complex menu structure
Study shows users prefer direct input opposed to a menu system
Menus are acceptable on a PDA where a stylus is used◦ Polyviou, Samaras and Evripidou implemented a
directory like interface
Survey of 45 students
Created 3 queries each of a University database
Unplanned queries still conformed to the relational level of query expressiveness
A relation that contains all other relations (universal)
Different attributes must have different names and the same attribute must have the same name in every relation it‘s present
Useful in the normalization process Reduces terms in query formation
Lack of foreign keys Use of precise terms Minimal term ambiguity
Relation names denote all attributes will be displayed
Attribute name denotes the attribute will be displayed
Conditions only in a query denote that all attributes of the first relation tested will be displayed
STUDENT SUBJECT SUBJECT.name STAFF.name SUBJECT STAFF.name STAFF.ID=112971 SUBJECT.crhr>3
Prototype developed on Java phone emulator
Interface is drop down menus◦ interface for small
devices should be simple and use as many as possible high-level APIs
Created on Nokia 6681
Part 1◦ Pre-determined queries, allowed to ask for help
Part 2◦ Custom queries, allowed to ask for help
Part 3◦ Custom queries, no help, rated
Part 4◦ Pre-determined queries, no help, rated
Groups’ Overall Effectiveness Scores
Query Types’ Overall Effectiveness Scores
Group # Score
Group 1 96.5%
Group 2 97%
Group 3 99%
Relational Operation
Score
Projection 100%
Selection 95.4%
Join (w/ out condition)
99.2
Join (w/ condition)
98.1
Union/Set Difference
100%
Creating a free-form query language for mobile devices is possible
Free-form language eliminates the need for Join and simplifies the number of query inputs
Usability tests show the language is effective
?
Rohiza Ahmad, Sameem Abdul-Kareem, "A Free-Form Database Query Language for Mobile Phones," 2009 WRI International Conference on Communications and Mobile Computing, January 2009, 279-284.