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!
Consider the relation PERSON. If you want to display details of persons having age less than or equal to 30 than the select operation will be used as follows:
σ AGE <=30 (PERSON)
The resultant relation will be as shown:
PERSON_ID
NAME
AGE
ADDRESS
2
Sharad Gupta
30
Pocket 2, Mayur
Vihar.
Note:
1) Select operation is commutative; i.e.,
σ (σ (R)) = σ (σ (R))
Therefore, series of select can be applied in any order
2) More than one condition can be applied using Boolean operators OR & AND etc.
Determine the OBJECTIVES of object design After passing through this unit, you should be able to: describe and apply concept of generalisation; understand and appl
Outer Join: The use of Outer Join is that it still joins those tuples that do not have matching values in common columns are also contained in the result table. Outer join places
Explain Clustering file organization (i) Determine if a record of file is physically ordered on a nonkey field - that does not comprise a different value for each record - that
If R1 and R2 are two union compatible relations or functions, then the result of R3 = R1 ∩R2 is the relation that contains all tuples that are in both the relations In other words,
Backward Recovery (UNDO): In this system the uncommitted changes made by a transaction to a database are undone. Instead the system is reset to the last consistent state of databa
One-way Associations When an association is traversed only in the one direction, then it is implemented as a pointer i.e.an attribute which contains an object reference. If mu
Data Base Management System 1. Draw the Architecture of MySQL and explain about its subsystems briefly. 2. Elaborate with the help of an example the concept of Primary key a
what is primary key
In E-R diagram how generalization is represented? in E-R diagram generalization is represented by Triangle shape.
What are the reasons for having variable length records? What are the various ways to store variable length records? Variable-length records arise in a database in various wa
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd