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= 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 196.5% Group 297% Group 399% Relational Operation Score Projection100% Selection95.4% 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

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 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,