Building Hybrid Database Applications

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Building Hybrid Database Applications

• Michelle Murrain
• Vice President for Technology
• Database Designs Associates, Inc.

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Presentation Overview

• What are hybrid applications?
• Why hybrid applications?
• What are their strengths and weaknesses?
• Lessons learned

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What are hybrid applications?

• Hybrid applications are client/server
  applications that use both open source and
  proprietary tools - open source on the server
  side, and proprietary on the desktop side
• Designed primarily for allowing different kinds
  of access to the same data web based, and
  desktop based
• Designed to deal with cross-platform issues - any
  OS can be used to access web version

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What are hybrid applications?

• In these specific examples, we have used open
  source database and web server back-ends, and
  Access or Crystal Reports desktop front ends
• Membership database
• Integration of web-based timesheet application
  with Access-based payroll system, and reporting
  with Crystal Reports
• Web-based incident reporting system integrating
  with existing Access database

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What are hybrid applications?

• School Evaluation system with pre-existing Access
  database, and web-based view of data for parents
  and students

Database
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Basic structure of a hybrid application
Linux Server
Windows Desktop
PostgreSQL
Open Source Web Application
odbc
Access
odbc
http
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Why Hybrid Proprietary/OS?

• Leverage open source server-side tools
• Tools like Linux, Apache, PostgreSQL, Perl, Open
  source web applications
• Mature, robust, secure, cost-effective, open
• In these situations, few end-user training issues

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Why Hybrid Proprietary/OS?

• These applications could be developed using
  entirely proprietary tools (such as Windows/SQL
  server)
• More expensive
• Less scalable, robust, stable and secure
• Closed
• Few inherent advantages

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Why Hybrid Proprietary/OS?

• Take advantage of flexible desktop tools
• Well-formatted and easy ad-hoc reporting
• Other strengths of Access and Crystal Reports
• Desktop interfaces are more powerful
• Use of a Windows desktop front end (most
  end-users have Windows and Office)
• Access allows for ad hoc data analysis and
  export, so that it overcomes some of the learning
  curve by letting users get at data and manipulate
  it in spreadsheet form.
• There are no open source database forms or
  reporting tools with the feature set of either
  Access or Crystal Reports

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Strengths

• Open source server (Linux-based, with Postgresql
  database and apache web server) This is a mature,
  robust and secure combination
• Open source web application tools - customizable
  and modifiable
• Strong desktop tools for development of reporting
  and some administrative tasks

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Weaknesses

• ODBC issues
• Security
• Behavior
• Consitency
• The web interface likely will require programming
• Both Access and Crystal Reports have steep
  learning curves
• Adopting the hybrid approach after one or the
  other application is in place (web app or Access
  database) may provide challenges because of the
  different ways Access and PostgreSQL deal with
  data

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Lessons Learned

• Its not all or nothing - you can use open source
  tools along with proprietary ones.
• The simpler the application, the easier it is to
  make it hybrid
• Making them talk nice to one another can
  sometimes be a challenge
• It may be more complicated than you expect,
  especially with very complex applications
• End users like the flexibility