A presentation about Real time databases......presented by group 6-Computer science students of University of Ruhuna

1. BY: GROUP 6

2. 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. 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. 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 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.  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.  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. 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 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.  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.  More efficient way of
handling large amount
of data.
 Specification of time
constraints.
 Improved overall
timeliness.
 Reduce development
cost.
 Avoid redundant data.

12.  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.  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. Presented by:
Nipuna Hewamaddumage
Thilina
Dinushika Rathnayaka
Nilshani Jayakodi
Yana Yonitha