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!
The Basic 2PL:The basic two phase locking allows release of lock at any time after all the locks have been obtained. For instance, we can release the locks in schedule of Figure, after we have gone through the values of Y and Z in transaction 11, even before the display of the sum. This will increase the concurrency level. The basic 2PL is given graphically in Figure.
Consider a bank that has a collection of sites, each running a database system. Suppose the only way the databases interact is by electronic transfer of money between one another,
Object-oriented decompositions Object-oriented decompositions of systems better are able to cope with change. Each subsystem has a well-defined interface which communicates with
What is self-transition? If there is a transition which goes back to same state, it is known as "self- transition." With a trigger action exit action would be executed f
Exclusive lock It is asked for by a transaction on a data item that it wants to update. No other transaction can put either a shared lock or an exclusive lock on a dat
Describe the two alternatives for specifying structural constraints on relationship kinds? Relationship kinds have certain constraints in which limit the possible combination o
(1) Insert into PERSON Violated constraint: - Key constraint Reason: - Primary key 1 already exists in PERSON. Dealing: - DBMS could ask the user to provide valid PER
Define the basic operations of the relational algebra? Ans: Basic operators of relational algebra are: 1. Union (∪) - Selects tuples which are in either P or Q or in bot
Type of views : Simple views and Difficult Views Feature Simple Views Complex Views Number of tables One
What are domain constraints? A domain is a set of values that might be assigned to an attribute .all values that appear in a column of a relation must be taken from the similar
An orchestra database consists of the following relations: CONDUCTS (conductor, composition) REQUIRES (composition, Instrument) PLAYS (Player, Instrument) Give the relational
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