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| Mobile Device Database Implementation | Database Training Sitemap |
| Submit Database Questions | Knowledge Transfer | Database Schedule |
| Definition of Service | Delivery Medium | Web-based Training Services |
Mobile Device Databases |
Performance Design |
| Operational Challenge | Mobile Database Systems | Mobile Database Implementation |
| 1- Client-side and 2-Offline Development | Performance Design | Best Practices - Mobile Database |
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A mobile application requires the appropriate selection of database software and development tools, identification and addressing of operational design challenges, and implementation of remote management. Evaluating and integrating free and low cost open source software into the database software stack will be important. Fundamental decisions associated with mobile database management include network storage and availability. When storing data locally on the mobile device for high availability and fast response times; the tradeoff will be increased power consumption and data concurrency on an enterprise system. Local data storage requires a plan for mobile data management and implementation. In addition to being stored on the device, data will need to be shared with enterprise data or through a web-based service. When data is being moved and updated by users, it will not be possible to lock the other databases each time a change is made. Fetching over the network and sending updates after the data has been modified or processed; this can be done by HTTP posts to a web service that updates the enterprise system. There will be issues in terms of availability and latency. The design objectives associated with a MDS: Mobile Database System are: 1- Availability. 2- Efficient interface and usability. 3- Reliable performance in conjunction with mobility usage. 4- Merge replication for database synchronization with the local database on the mobile device with the central database server. 5- Importing and exporting data to the database server in conjunction with synchronization. 6- Scalability to accommodate synchronization. The assumption is that use of a MDS with a leading enterprise database affords a minimal risk implementation.
Mobile Database Implementation Mobile databases can be designed and coded to use indexes, transaction processing, referential integrity, multi-table joins, row-level locking, SQL functions, BLOB support, and location-based data. Implementation of a database specific to a mobile device includes:
There has been a significant increase in web development integrated into mobile applications. There are issues which need to be addressed in terms of design, coding, and user acceptance: 1- intermittent network availability. 2- client-side database storage. HTML5 offers data storage within tables defined with the SQL: Structured Query Language; it is used for storing large amounts of information. There also are localStorage and sessionStorage objects for storing strings of information; it is easier to implement and has fewer restrictions. The tradeoff is storing less information. With persistent storage, information is saved, until it is erased. In session storage, the information is stored specific to the session. All the pages of a website can access information stored in the session up through the closing of the application. Persistent and temporary storage do not provide facilities comparable to a relational database through SQL. The localStorage and sessionStorage JavaScript objects are used to implement the facilities: 1- The localStorage allows permanent storage. 2- The sessionStorage allows storage in the session. HTML can be used to make a local SQL database available with JavaScript. Once access to the database is established, tables can be created and deleted and data can be inserted, retrieved, and deleted. A JavaScript program can be coded with jQuery Mobile to access data stored in a local database, without accessing a server. HTML contains the displayed data and the default rendering. The HTML elements of the page are organized in a hierarchy of the HTML DOM: Document Object Model tree. User-initiated events cause a conventional request-response cycle with a page load and the execution of associated JavaScript functions. The JavaScript element contains the controller functions of the application with event handlers used for binding the JavaScript functions. JavaScript accesses the UI: user interface elements of the HTML DOM tree
as data input for processing and presentation to the HTML page. The CSS: Cascading Style Sheet provides the instruction for rendering the HTML page. There are JavaScript/CSS libraries and frameworks for mobile
device web applications. The deployment descriptor component is through a manifest file which provides the list of files required to be loaded for an offline web application. In most cases, a mobile version of an application will need to extend the desktop application and translate into customer value and utility for mobile users. The assumption is that the presentation of data will incorporate the execution of business processes
within an industry standard development environment: A plan will be needed for scalability and changes to enterprise database for supporting mobile synchronization: Due to the mobility of both data and users and frequent disconnection, transactions might have to split computations into sets of operations: |
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Google Corporation observed that a half second delay caused a 20% reduced usage in traffic. Experiments by Amazon Corporation with delayed page loading from its data center web site operations indicated that small delays result in substantial and costly drops in revenue.