WebEnabled Databases

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Web-Enabled Databases

• Daniel Chappell

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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

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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 DBs underlying
  design (only has to worry about the web
  interface)
• Similarly, the DB designer need not concern
  himself with the DBs web interface (only with
  how the DB schema are designed)

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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 WEDs interface to the
  outside world
• Middleware layer consists of some logic to
  translate a users 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.

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WED Architecture II
User - Interface - Middleware - Database -
Middleware - Interface - User
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WED Users

• WED are used all the time, sometimes even without
  the users 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 who
  needs 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!

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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)

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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)

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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!)

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WED Ease of Use I

• Would Anyman User rather use this

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WED Ease of Use II

• or this?

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WED Disadver, 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)

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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.

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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)

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References

• University of Michigan http//download.101com.com
  /syllabus/conf/summer2004/PDFs/T07.pdf
• Interact http//www.ltss.bris.ac.uk/interact/18/i
  n18p05.html
• Wikipedia http//en.wikipedia.org/wiki/Database
• Research Databases Group http//www.nottingham.ac
  .uk/is/about/news/newsletter/inform-online-7.4/dat
  abases.htm