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Published byClyde Green Modified over 8 years ago
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Kevin Pheasey
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Introduction Related Work How the language was implemented Main concepts of query language Test
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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
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Support for different types of queries as well as unplanned queries Use Minimal Resources Be easy to use given the restricted screen size
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Current query languages are restricted by the domain of the application ◦ Hung and Zhang telemedicine system ◦ Kobayashi and Paungma transportation system
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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
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Survey of 45 students Created 3 queries each of a University database Unplanned queries still conformed to the relational level of query expressiveness
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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
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Lack of foreign keys Use of precise terms Minimal term ambiguity
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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
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STUDENT SUBJECT SUBJECT.name STAFF.name SUBJECT STAFF.name STAFF.ID=112971 SUBJECT.crhr>3
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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
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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
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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%
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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, 279-284.
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