Define physical and logical data independence, Database Management System

Assignment Help:

Define physical and logical data independence. How does this architecture help in achieving these?

Data independence entails that change in one view must not need a change in the view(s) above. There are two sorts of data independence: logical and physical. The meaning of Logical data independence is that the conceptual view can be changed without influencing the existing external view, that is a given record may be spilt or combined along with other records but the external views need not be modified to reflect this. The meaning of Physical data independence is that the physical storage structures or devices employed to store the data can be changed without effecting the existing conceptual view or external view, that is if earlier indexed sequential files are employed to store data and then the B- trees are used, even then the upper layers must not be effected.


Related Discussions:- Define physical and logical data independence

What is a view, What is a view? A view is a logical view on one or more...

What is a view? A view is a logical view on one or more tables.  A view on one or more tables i.e., the data from a view is not actually physically kept instead being derived f

What are the time stamps associated with each data item, What are the time ...

What are the time stamps associated with each data item? W-timestamp (Q) denotes the largest time stamp if any transaction that implemented WRITE (Q) successfully. R-timesta

Discuss difference between drop table r and delete from r, Discuss The diff...

Discuss The difference between drop table R and delete from R.  DROP TABLE command deletes all the records with the table definition. This command will automatically committed

#cursor, #what is cursor its uses ? Explain it

#what is cursor its uses ? Explain it

Requirements for your cache simulator, Using your cache simulator and using...

Using your cache simulator and using smalltex.din as your memory trace determine the total miss rate, compulsory miss rate, capacity miss rate, and conflict miss rate for the follo

What is the need for triggers, What is the need for triggers? Triggers ...

What is the need for triggers? Triggers are useful mechanisms for alerting humans or for starting particular tasks automatically when particular conditions are met.

What is trigger, What is Trigger? Trigger: A database trigger is proced...

What is Trigger? Trigger: A database trigger is procedural code which is automatically executed in response to specific events on a particular table in a database. Triggers can

Define blocks, Define blocks? The database system resides eternally on ...

Define blocks? The database system resides eternally on non-volatile storage, and is into fixed-length storage units known as blocks.

Data Minnning, Can i get help with weka software

Can i get help with weka software

Describe domain constraints, Describe domain constraints. Domain constr...

Describe domain constraints. Domain constraints contain entity integrity and referential integrity. The domain is a set of values that might be assigned to an attribute. The en

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd