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