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Web-Enabled Databases

Web-Enabled Databases. Daniel Chappell. The Notorious Outline!. Web-enabled Databases (WED): What Are They? WED: Who Uses Them? WED: Advantages WED: Common Challenges (diplomatic way of saying “disadvantages”) WED: Current Research. WED: A Definition.

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Web-Enabled Databases

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  1. Web-Enabled Databases Daniel Chappell

  2. The Notorious Outline! • Web-enabled Databases (WED): What Are They? • WED: Who Uses Them? • WED: Advantages • WED: Common Challenges (diplomatic way of saying “disadvantages”) • WED: Current Research

  3. WED: A Definition • Web-enabled Database: simply put, a database with a web-based interface • This implies that there can be a separation of concerns; namely, the web designer does not need to know the details about the DB’s underlying design (only has to worry about the web interface) • Similarly, the DB designer need not concern himself with the DB’s web interface (only with how the DB schema are designed)

  4. WED: Architecture I • A WED typically uses 3 tiers (also called layers) to function: a presentation layer, a middleware layer, and the database layer. • Presentation layer: concerned only with the actual “look and feel” that an outside user would experience; this is the WED’s interface to the outside world • Middleware layer: consists of some logic to translate a user’s input, mouse clicks, and the like into a format a database can understand; this layer essentially converts the input from the presentation layer into database-useable form (and back again for the results) • Database layer: the actual database itself, such as a PostgreSQL database. This layer contains the tables to be queried and the information that the user seeks to retrieve.

  5. WED Architecture II User -> Interface -> Middleware -> Database -> Middleware -> Interface -> User

  6. WED: Users • WED are used all the time, sometimes even without the user’s realization • The WED model is best used in situations where: • users are geographically disparate • information is needed by many people • information must be centralized • a “pull” model for information access and retrieval is needed • Thus, the most common user of a WED is one whoneeds to access information on demand from a central data repository, yet may be located far away from the actual location of the database itself • Our final project will be the design and implementation of a WED, too!

  7. WED: Advantages • Pull vs. Push: a web-enabled database allows users to get the information they need from a central repository on demand • Ease of Use: much simpler for John Q. Public to interact with a web interface than a command-line • Access: can easily access information in the database from anywhere one can get a web connection (does not require a separate program/protocol, such as SSH)

  8. WED: Pull vs. Push • Push Model: some central authority just hands out necessary information whenever something important happens (example: dept. secretary sends out a memo to faculty to notify everyone of an upcoming event) • Pull Model: each part of a system queries a central authority whenever it needs information; the central authority then sends the necessary information as requested (continuing the analogy, this would be like a faculty member calling the dept. secretary for information about a certain event)

  9. WED: Access • In a WED, anyone with a web connection can access the information contained in the database. As an example, consider Fandango.com. With it, I can easily access all the movie theaters near me to find information about movies that interest me (note to self: go see the new Harry Potter movie!)

  10. WED: Ease of Use I • Would Anyman User rather use this…

  11. WED: Ease of Use II • …or this?

  12. WED: Disadv…er, Challenges • Access: like command-line databases, users must be divided into access groups; this detracts from the ability of any user to get any and all info he/she desires • Primitive Designs: WEDs support the full range of DB operations, but, in order to make them easy to use, they must be “dumbed down” • Denial of Service (DoS): just like any other web service, a WED can be attacked by hackers to cause a DoS to legitimate users, making access to information difficult (if not impossible)

  13. WED: Access (Downsides) • Since users must be divided into groups, it is inevitable that some outside users would love to get a high level of access so they can get information to which they ought not be privy • This is the main disadvantage of a WED: it can be hacked through typical means (password theft and the like) • Have you ever heard about credit card companies and banks getting their database systems hacked? The same thing is possible with a WED.

  14. WED: Current Research • Design: as mentioned previously, a WED can be a rather primitive construct; thus, more sophisticated methods for the creation and maintenance of a WED are a major thrust in WED research (see U of Michigan) • Information Storage and Dissemination: much research is in the area of how to model and store information, and then how to access it with a web interface (see Interact)

  15. References • University of Michigan:http://download.101com.com/syllabus/conf/summer2004/PDFs/T07.pdf • Interact:http://www.ltss.bris.ac.uk/interact/18/in18p05.html • Wikipedia:http://en.wikipedia.org/wiki/Database • Research Databases Group:http://www.nottingham.ac.uk/is/about/news/newsletter/inform-online-7.4/databases.htm

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