Mobile database access with a Pocket PC

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Mobile database access with a Pocket PC

• Rutherford Associates.
• http//www.eostar.com
• June 14, 2005
• West MI .NET Users Group
• Michael Rutherford
• Jovo Filips

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PresentersRutherford Associates, Inc.

• Rutherford Associates, Inc.
• Rutherford Associates specializes in
  line-of-business applications for the
  distribution industry.
• Michael Rutherford
• Michael Rutherford is CEO and President of
  Rutherford Associates. Michael's career spans
  several industries (scientific, government,
  medical and distribution) and several programming
  languages over several decades.
• Jovo Filips
• Jovo Filips is Vice President at Rutherford
  Associates. Jovo has been involved in large-scale
  IT projects spanning nearly 20 years with direct
  involvement with network design, application
  development, database design and multi-state
  deployments.

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TopicMobile database access in a high-volume
transaction based system

• SQL Considerations
• Design and scalability issues from the MS SQL
  side of the solution
• Mobile (Pocket PC) Considerations
• Design, scalability and implementation issues
  from the mobile side of the solution

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MS SQL Design Considerations for Mobile Data
Access

• Michael Rutherford

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Design overview
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SQL Considerations

• Triggers
• Pre-Accumulate Information
• Query Plan
• No embedded parameters
• Transaction
• Reliability
• History
• Auditing faults

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Web Service Considerations

• Performance
• When everyone posts data at the same time .. ?
• Reliability
• When communication fails. ?
• Scalability
• Session-less

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Pocket PC Considerations

• Reliability
• Always on
• Performance
• Data object must be efficient
• Usability
• Replaces route books
• Seamless integration

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Pocket PC Design Considerations for Mobile Data
Access

• Jovo Filips

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Pocket PCOperational Environment

• Salespeople needs
• Up-to-date Customer, Product, Inventory, Pricing
  information
• Up-to-date Sales Analysis information

• Delivery people needs
• Accurate Customer and Order information
• Audit capabilities for delivery vehicle inventory
  and cash reconciliation

All these needs and others make deep impact on
design goals
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Pocket PCDesign Goals

• Speed
• Performance needs
• Usability
• Unobtrusive interfaces
• Reliability
• The mobile user trust
• Scalability
• Everyone will synchronize at the same time

Bottom Line Mobile users dont want to use your
application. They want to go home.
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Pocket PCData Storage Tools

• Local Storage
• Pocket SQL
• Big (Mbytes), Slow (not sub-second)
• But.. Flexible
• Proprietary Serialized Objects
• Tight (Kbytes), Quick (sub-second)
• But.. Can be high-maintenance
• ADO .. ?
• Not much of a concern for live applications

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Pocket PCData Synchronization Tools

• Pocket SQL lt-gt MS SQL
• Built-in publisher-subscriber tools
• Slow, Slow, Slow on Pocket SQL 1.0
• Massive data payload
• Easy to setup
• Deployment sucks
• Private Objects lt-gt MS SQL
• Roll-your-own replication
• Needs translator (web service)
• Increases complexity
• Data payload is as efficient as possible

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Pocket PCData Storage and Synchronization
Design Summary

• Users dont care how you store
• UNLESS it impacts speed, reliability and
  usability
• Users dont care how you synchronize
• UNLESS it impacts speed, reliability, usability
  and keeps them from going home

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Pocket PCWhat Rutherford Did

• Private object storage
• Speed
• Reliability Replicate locally
• ASP.NET Web Service
• Speed
• Scalability