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!
If the deletion violates referential integrity constraint, then three alternatives are available:
Example:
Let R:
A#
B
C^
A1
B1
C1
A2
B3
C3
A3
B4
A4
C5
Q
C#
D
D1
D2
D3
Note:
1) '#' shows the Primary key of a relation.
2) '^' shows the Foreign key of a relation.
(1) Delete a tuple with C# = 'C1' in Q.
Violated constraint: - Referential Integrity constraint
Motive: - Tuples in relation A refer to tuple in Q.
Dealing: - Options available are
1) Decline the deletion.
2) DBMS may automatically delete all tuples from relation S and Q with C
# = 'C1'. This is known as cascade detection.
3) The one more option would result in putting NULL value in R where C1 exist, which is the initial tuple R in the attribute C.
#questiRegional Gardens has many nurseries, including Wagga Wagga, Bathurst, Albury, Orange, and Dubbo. Each nursery is known by its campus code, eg WW, B, A, O and D respectively.
A video rental company has several branches. The data held on each branch is the branch address made up of street, city, state, and zip code, and the telephone number. Ea
I have to solve a problem using access
What is the difference between SQL Server 2000 complete and differential backups? A complete backup makes a copy of the whole database. A differential backup creates a copy of
Two Phase Locking (2PL) The two-phase locking protocol having of two phases: Phase 1 : The lock acquisition phase : If a transaction T needs to read an object, it wants to
In case of entity integrity, the primary key may be declared? In a case of entity integrity primary key may be not Null.
A domain is a set of permissible values that can be given to an attribute. So each attribute in a table has a definite domain. Values to these attributes cannot be assigned outside
Define the phases of two phase locking protocol Growing phase: a transaction may get locks but not release any lock. Shrinking phase: a transaction might be release locks bu
Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pictori
The physical location of a record is determined by which mathematical formula that transforms a file key into a record location? The physical location of a record is determined
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