Developing PocketPC Applications for a SemiConnected Environment

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Developing PocketPC Applications for a
Semi-Connected Environment

• Malek Kemmou
• CEO Arrabeta
• kemmou_at_kemmou.com

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• CEO Arrabeta (consulting firm based in
  Casablanca Morocco)
  
• Newtelligence Alliance Partner
• Senior Consultant and Senior Trainer
  
• Solutions Architecture, integration,
  interoperability
• Microsoft Regional Director for Middle East
  and Africa
• Ineta MEA Speaker Bureau
• Speaker at many conferences and events
  (TechEd, NDC, MDC, DevDays, DevEssentials )

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Microsoft Regional Directors

• http//www.microsoft.com/rd
• 140 experts from all around the world
• Speaking at PDC 2004
• Clemens Vasters (Germany)
• Stephen Forte (New York)
• Farhan Mohammad (Minesota)
• Goksin Bakir (Turkey)
• Malek Kemmou (Morocco)
• Ahmad Badr (Egypt)
• Hossam Khalifa (Egypt)

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Agenda

• A semi-connected World
• The Challenge of Data Persistence
• Storage possibilities
• I/O
• Pocket Access
• SQL Server CE
• Synchronizing the Data
• Web Services
• Merge Replication
• RDA

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Our World

• Business is conducted everywhere
• Distribution, Customer Relations
• Shipping
• Field Industries Construction, Civil
  Engineering, Telecom Infrastructure, Media
• Consulting, Support
• Travel Industries

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Our World

• Customers are everywhere
• On the street, at work, at home, at the zoo
• Traveling, roaming
• Out in the mountains, in rural areas
• Wherever people are, there are business
  opportunities
• Sales
• Customer satisfaction

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Our World

• Information is crucial
• Agile Business need
• Faster access to information
• More reliable and up to date information
• More reactivity to available information

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Our World

• Connectivity is
• Not everywhere (Infrastructure)
• Expensive on the field (GSM / GPRS / )
• Slow (bandwidth)
• GSM 14.4 kbs
• GPRS 28.8 kbs
• Not very reliable
• Network congestion
• Discontinuity

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Semi-Connectedness

• Get connected
• At the office, before leaving for the field
• On the field, using any form of connectivity
  available
• Fetch and persist Data
• Use the data in disconnected mode
• Consume
• Modify
• Get Connected and Synchronize Data

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Data Persistence

• Challenge
• Small device
• Portable power (batteries)
• Security (device can be easily stolen or lost)
• Need for secure, light weight, usable format
  storage

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Storage Locations

• File IO
• Easy to develop
• Not very easy to deploy (number of devices)
• Can use synchronization mechanisms
• Usability depends on format
• XML easy to use, heavy weight. Fit for small
  amounts of Data
• Text (CSV, position ) light weight on storage,
  not flexible, needs parsing / formatting
  (performance?)

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Storage Locations

• Pocket Access
• No managed providers
• Not very easy to deploy (number of devices)
• Can use synchronization mechanisms
• No Replication mechanism with SQL Server
• Usable if managed providers are developed
• Can use third party tools

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Storage Locations

• SQL Server CE
• Managed providers
• Two synchronization mechanisms
• Can also easily be populated by code
• Easy to use
• Familiar relational database access
• Performance
• Efficiency
• Compacted Data on transfer and on storage

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SQL CE Supported Platforms

• PocketPC 2002, 2003, Phone Edition
• Managed support
• .NET CF in ROM for Pocket PC 2003
• Native support
• eVC v4.0 via OLEDBCE
• Embedded
• Next release of Windows CE.NET codenamed Macallan
  
• Managed support
• Native support
• eVC v4.0 via OLEDBCE

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Demo

• Creating and populating
• A SQL CE Database
• Through code

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Database Feature SetRich functionality for small
footprint

• Multi-column indexes
• Referential integrity
• Sub-selects (IN)
• Defaults
• Inner/outer joins
• One file database
• Null support
• Unicode support
• Transactions

• Data-types
• Real, Numeric, NVarChar, NText, Image, Integer,
  DateTime, VarBinary, UniqueIdentifier, Money
• Having/group by
• Seek on index
• Set functions
• Identity attribute
• Local security - DB encryption (128bit) and
  database password

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Deployment considerations

• Database stored on sdf file
• Deployment Options
• Active Sync (small number of devices, common
  Data)
• Flash cards
• Code (application creates Database at start)
• Permits using code to populate (Docked State)
• Delete / recreate

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Populating with Data

• Query Database on server and store locally
• Usable with other than SQL Server
• Highly flexible (implement your own logic)
• Low performance, easy and dirty
• Use Replication
• Highly performing compacting algorithms
• Leverage IIS and SQL security
• Replication approach, two way, keep track of
  changes
• Two techniques
• Remote Data Access (RDA)
• Merge Replication

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SQL CE Architecture
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Connectivity  Transport

• Utilize Web technology
• HTTP communication
• Internet and Intranet
• Security via IIS
• Authentication (anonymous, basic, NTLM)
• Authorization
• Encryption for secure transfer (SSL)
• Access through firewalls

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ConnectivityMerge Replication

• SQL Server 2000 features crucial for SQL Server
  CE
• Vertical and horizontal partitioning
• Dynamic horizontal filters
• Auto ranged identity columns
• Standard/custom conflict resolvers

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Merge Replication APIs

• System.Data.SQLServerCe.SqlEngine.CreateDatabase
• Replaces AddSubscription Method
• Creates blank database
• System.Data.SQLServerCe.Replication.Synchronize
• Initial Sync
• Creates schema, downloads data, creates
  constraints
• Subsequent Sync
• Push modified data up, then bring modified data
  down

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Demo

• Merge Replication

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ConnectivityRemote Data Access

• Access to SQL Server 7.0 SQL Server 2000
• Download to device and disconnect
• Disconnected tracking capability
• Extremely easy to setup and use
• Effective scaling

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RDA APIs

• System.Data.SQLServerCe.RemoteDataAccess.Pull
• Brings data from server to device
• Data selected via SQL statements
• Creates and populates local table
• Allows for tracked and untracked data
• System.Data.SQLServerCe.RemoteDataAccess.Push
• Sends modified data to server
• System.Data.SQLServerCe.RemoteDataAccess.SubmitSQL
  
• Pass SQL DML statement

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Demo

• Remote Data Access

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Small Data ExchangeWeb Services

• Limited serialization possibilities
• No typed DataSet
• No access to XMLSerializer from .Net Compact
  Framework
• Use structures
• For Datasets, can use diffgrams
• Useful for
• reuse of existing services
• Small temporary data
• No direct access to Database from the Web

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Demo

• Web Service Client

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Summary

• Developing for a semi-connected environment
• Persisting data
• I/O (small semi-static data)
• SQL Server CE
• Local Execution
• Easy to develop with .Net Compact Framework
• Reuse of existing business logic
• Synchronizing
• Web Services
• Merge Replication
• Remote Data Access

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Questions ?

• http//www.malekkemmou.ma
• kemmou_at_kemmou.com