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real time databases

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ppt about real time databases.....create by group 6-BCS batch 2013/14-University of ruhuna – PowerPoint PPT presentation

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Updated: 26 October 2014
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Title: real time databases


1
Real Time Databases(RTDB)
BY GROUP 6
2
Whats a Real Time System?
  • A system which its basic specifications and
    design
  • correctness arguments have ability to meet its
    time
  • constraints.
  • Correctness depend on both logical correctness
    and timeliness of its actions
  • Deal with temporal data
  • Response must be produced within a specific time
    , otherwise data become out dated

3
Whats a Real Time Database?
  • A database system
  • which uses real time
  • processing to handle
  • workloads whose state is
  • constantly changing.
  • Timely execution of transactions with the ACID
    properties.
  • Operations execute with predictable response ,
    and with application-acceptable levels of logical
    and temporal consistency of data

4
Related Topics......
  • Transaction sequence of read and write
    operations.
  • ACID properties
  • Atomicity transaction is done either completely
    or not at all
  • Consistency transactions are executed in a given
    sequence
  • Isolation actions of a transaction are not
    visible to any other transactions until it is
    committed
  • Durability transactions of a database are
    permanent

5
Timing constraints and Deadlines
  • Timing constraint associated with transactions
    with deadlines.
  • Timing constraint types
  • Hard must execute before deadline
  • Firm abort if not completed by deadline
  • Soft diminished value if completed after
    deadline

6
Why Real Time Databases?
  • As the complexity of Real Time Systems going up ,
    the amount of transactions to be handled by real
    time systems increases.
  • Conventional databases do not support timing and
    temporal requirements.
  • Design objectives of
  • conventional databases
  • are not appropriate
  • for real time applications.

7
Types of Real time databases
  • Soft real time database systems
  • These are databases used in non-critical real
    time systems where missed transactions only
    degrade system quality.
  • E.g. databases in banking, stock market, and
    airline reservation systems
  • Hard real time database systems
  • These are databases used in critical real-time
    systems used in places such as nuclear power
    plants.
  • E.g. databases in early warning systems,
    Emergency alarm systems, MDARTS
  • MDARTS stands for multiprocessor database
    architecture for real time systems. This is used
    mainly in control applications, such as
    controlling machine tools and robots etc

8
Features of RTDB...
  • Has The ACID properties
  • Has timing constraints
  • Timeliness is more important than correctness
  • Queries to the database should have soft or hard
    deadlines
  • Data returned must have both absolute consistency
    and relative consistency
  • Deal with temporal data that become outdated
    after a certain time
  • Not all data are permanent but temporal, e.g.,
    sensor data or stock prices
  • Both real-time scheduling database technologies
    can be applied to real-time data management

9
Data in RTDBs....
  • Data items reflects the state of environment.
  • Data from sensors. e.g. temperature, humidity,
    pressure etc
  • Derived data. e.g. rate of reaction
  • Input to actuators. e.g. amount of chemical
  • Archival data. e.g. history of(interaction
    with) environment
  • Static data(as in conventional data bases)

10
Difference Between Real Time Conventional
Databases
  • Real time databases have to deal with temporal
    data compared to static data as the case of
    traditional databases.
  • Unlike traditional databases , timing constraints
    are associated with the different operations
    carried out on real time databases.
  • Main objective of conventional databases is to
    provide fast average responce.But RTDBs focus
    on average transactions miss their deadlines(also
    the cost incurred for late transactions).

11
Advantages of RTDBs...
  • More efficient way of handling large amount of
    data.
  • Specification of time constraints.
  • Improved overall timeliness.
  • Reduce development cost.
  • Avoid redundant data.

12
Objectives of Real Time Databases
  • Dealing with time constraints and violations.
  • Get the maximum benefit from results which
    generate from actions completed in time.
  • Minimize the damage which occurs from actions
    that delayed or not executed in time.

13
Services of RTDBs
  • Telecommunication systems
  • Routers and network management systems
  • Telephone switching systems
  • Control systems
  • Automatic tracking and object positioning
  • Engine control in automobiles
  • Multimedia servers for real-time streaming
  • E-commerce and e-business
  • Stock market program stock trading
  • Financial services e.g. credit card
    transactions
  • Web based data services

14
THANK YOU
Presented by Nipuna Hewamaddumage Thilina Dinu
shika Rathnayaka Nilshani Jayakodi Yana
Yonitha
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