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!
Explain the Concept of Two-phase Locking
It concerns the positions of locking and unlocking operations in each transaction. In this protocol every transaction issue lock and unlock requests in two phases.
Growing Phase: In this phase a transaction might acquire locks but may not release any lock. Here the of locks rises from zero to the maximum for the transaction.
Shrinking Phase: In this phase a transaction might release locks but may not obtain any new locks. Here the number of locks reduces from maximum to zero.
The major concept of this protocol is that, all the locks are first obtained before any of the locks released. No new locks can be granted later than the releasing of any lock.
coventions for displaying an ER schema as ER diagram
Insulation between conceptual and physical structures It can be defined as: 1. The Database Administrator should be capable to vary the storage structures without affectin
How are tables stored on Disk? We realise that every record of a table can have different amounts of data. This is due to in some records; some attribute values may be "zero".
Insertion Anomaly: Inability to show certain information-The primary key of the over relation be (enrolment number, Cno). Any new tuple to be inserted in the relation should have
as a customer service employee, explain five measures you would recommend a displeased student to patronise a school canteen
Need 2 projects completed in 3NF format.
Define canonical cover? A canonical cover Fc for F is a set of dependencies like F logically implies all dependencies in FC and Fc logically shows all dependencies in F.
Determine Which is not a consequence of concurrent operations? Ans: Update anomaly.
why shadow copy technique is used?
What is an object ID? Each class-derived table has an ID for primary key, one or more object IDs form primary key for association derived tables. An object ID is equivalent dat
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