1 / 15

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.

jana
Télécharger la présentation

Web-Enabled Databases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related