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!
Define Query by Example
QBE is a query language relies upon domain calculus and has two dimensional syntax. The queries are written in the horizontal and vertical dimensions of table. Queries are made by entering an instance of a possible answer in a skeleton table as displayed in the following diagram:
Conditions particular in a single row are ANDed and conditions illustrated in separate rows are ORed. The tuple operations are P., I ., etc., for PRINT, insert commands, resp. The variable names are illustrated by preceding their name with an underscore. QBE as well provides a "conditions" box to specify additional constraints that is why the conditions that cannot be added in a Skelton table can be entered in the conditions table. The aggregation operations such as max., min, sum. etc. are also provided by QBE.
Explain the Difference between DROP and DELETE DELETE deletes one or more than one tuples of a particular relation from the database. DROP is employed to remove a table from th
1. Determine the set of minimal functional dependencies for the following data. The local bakery, Happy Cakes, needs your help designing a database that will support a kiosk in
Define a property that is not a property of transactions? Ans: Concurrency is not a property of transactions
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4
why we fregment at all?
what are the states of transaction?
Vertical Fragmentation- Vertical fragmentation groups together only those attributes in a relation that are used jointly by various important transactions. A vertical fragment is d
Define union compatibility? Explain why INTERSECTION of two relations cannot be performed if they are not union compatible? Two relations R(A1, A2,-------, An) and S(B1, B2,--
Define the notation for classes and atrributes The notation for class, attribute, and operations are shown below: Figure: Class with attributes and operations A
external and internal mapping with examples
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