Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Saving Derived Attributes to Avoid Re-computation
As discussed, "redundancy means duplication of exact data". But, if multiple copies of same data are present in the system, then it can increase chance of availability of data, but the problem of computing overhead is also associated with it.
To overcome this difficulty we can "cache" or store the redundant data in its computed form and classes or objects might be defined to retain this information. The class which contains cached data must be updated if any of objects that it depends on are changed.
Figure shows use of derived object and derived attribute in OMTool. Each class box contains an ordered list of operations and attributes, each represented as text string (left of diagram). Given the location of the class box itself, the location of each attribute can be computed by adding up the size of all the elements in front of it. Since location of each element is required frequently, location of each attribute string is computed and then stored. The region containing entire attribute list is also computed and saved. In this way, you can avoid the testing of input points against the attribute text element. It is shown in the right side in Figures. If a new attribute string is added to list, then locations of the ones after it in list are simply offset by size of the new element.
Figure: Derived attribute to avoid re-computation
Describe in brief about DBMS ?
Describe about Use Case and external case in DFD The processes are transformed those into the Use Case and external case in DFD has same characteristics which of an actor in O
Explain Thomas' Write rule. Show how it is different from timestamp ordering protol Ans: In timestamp-based concurrency control the thomas Write rule is a rule. Given a Timest
cardnality ratio for humanresource mangement system
Key to represent relationship amongs tables is called ? A Key that represent the relationship between tables is called Foreign Key.
Use a Set operator to create a list of academics who have written or co-written less than 5 papers and also have greater than 3 interests. List their academic number in the output.
Why DML is used for? DML is used to Manipulation and processing of database. DML is provided for manipulation & processing of database. (Data stored in the database is processed
Why did SAP introduce the extended star schema? Explain why it is reported to be better than the traditional schema model?
Guidelines for creation of table: Table name should begin with an alphabet. In table name, single quotes and blank spaces are not allowed. Reserve words of that DBM
why are older data models are being replaced by new data models
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd