Define the wait for graph, Database Management System

Assignment Help:

Define the Wait for graph

Ans: The wait-for-graph is a directed graph and consist of nodes and directed arcs; the nodes of the graph are active transactions. An arc of the graph is inserted among two nodes if there is a data-item is needed by the node at the tail of the arc that is being held by the node at the head of the arc. If there is a transaction Ti, waiting for a data-item that is presently allocated and held by transaction Tj, after that there is a directed arc from the node for transaction Ti, to the node for transaction Tj. The wait-for-graph is employed for detection of deadlock in the system. If there is cycle exits in the graph, all the transaction (denoted as nodes) are in deadlock, which are in the cycle.


Related Discussions:- Define the wait for graph

Examine about the behavioural diagrams, Examine about the Behavioural Diagr...

Examine about the Behavioural Diagrams  The main objective of behavioural diagrams is to visualize, specify, construct and document dynamic aspects of a system. The interactio

What is a hash index, What is a hash index? A hash index organizes the ...

What is a hash index? A hash index organizes the search keys, with their associated pointers, into a hash file structure.

gaps in sequence values can happen when-sequences, Gaps in sequence values...

Gaps in sequence values can happen when: -     A rollback happens that is when a statement changes are not accepted. -     When the system crashes -     When a sequence i

How is the database organised in oracle, How is the database organised in O...

How is the database organised in Oracle? Database organized within Oracle in terms of table and table holds attributes and values. A database consists of one or more logical

Need for distributed database systems, Need For Distributed Database System...

Need For Distributed Database Systems A distributed database is a set of database kept on multiple computers that appears to applications as a one database. As a result, an app

Stored and derived attributes, Attributes that are directly kept in the dat...

Attributes that are directly kept in the data base. For example, 'Birth date' attribute of a person.   Derived  Attributes that are not stored directly but can be derived

Security-drawbacks of data distribution, Security: In a centralised system...

Security: In a centralised system, access to the data can be simply controlled. Though, in a distributed DBMS not only does access to replicated data have to be controlled in many

What is 2nf, What is 2NF? A relation schema R is in 2NF if it is in 1NF...

What is 2NF? A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R is fully functionally dependent on primary key.

Keys, #questiontypes of keys examples..

#questiontypes of keys examples..

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd