Multiversion Concurrency Control Techniques
Q. What is multiversion concurrency control technique? Explain how multiversion concurrency control can be achieved by using Time Stamp Ordering.
Deadlocks-An Unconditional Waiting Situation in Operating System. We must make sure of This concept well before understanding deep in to Operating System. This PPT will understands you to get how the deadlocks Occur and how can we Detect, avoid and Prevent the deadlocks in Operating Systems.
Deadlocks-An Unconditional Waiting Situation in Operating System. We must make sure of This concept well before understanding deep in to Operating System. This PPT will understands you to get how the deadlocks Occur and how can we Detect, avoid and Prevent the deadlocks in Operating Systems.
THIS DESCRIBES VARIOUS ELEMENTS OF TRANSPORT PROTOCOL IN TRANSPORT LAYER OF COMPUTER NETWORKS
THERE ARE SIX ELEMENTS OF TRANSPORT PROTOCOL NAMELY
1. ADDRESSING
2. CONNECTION ESTABLISHMENT
3.CONNECTION REFUSE
4.FLOW CONTROL AND BUFFERS
5.MULTIPLEXING
6.CRASH RECOVERY
INTRODUCTION
WHAT IS OSI?
OSI MODEL
TYPES OF LAYERS
PHYSICAL LAYER
DATA LINK LAYER
NETWORK LAYER
TRANSPORT LAYER
SESSION LAYER
PRESENTATION LAYER
APPLICATION LAYER
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some PagesAre Not in Main Memory
Steps in Handling a Page Fault
Multi version concurrency control techniques
This approach maintains a number of versions of a data item and allocates the right version to a read operation of a transaction. Thus unlike other mechanisms a read operation in this mechanism is never rejected.
THIS DESCRIBES VARIOUS ELEMENTS OF TRANSPORT PROTOCOL IN TRANSPORT LAYER OF COMPUTER NETWORKS
THERE ARE SIX ELEMENTS OF TRANSPORT PROTOCOL NAMELY
1. ADDRESSING
2. CONNECTION ESTABLISHMENT
3.CONNECTION REFUSE
4.FLOW CONTROL AND BUFFERS
5.MULTIPLEXING
6.CRASH RECOVERY
INTRODUCTION
WHAT IS OSI?
OSI MODEL
TYPES OF LAYERS
PHYSICAL LAYER
DATA LINK LAYER
NETWORK LAYER
TRANSPORT LAYER
SESSION LAYER
PRESENTATION LAYER
APPLICATION LAYER
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some PagesAre Not in Main Memory
Steps in Handling a Page Fault
Multi version concurrency control techniques
This approach maintains a number of versions of a data item and allocates the right version to a read operation of a transaction. Thus unlike other mechanisms a read operation in this mechanism is never rejected.
This will tell about the three of the Protocols(Lock-Based Protocols, Timestamp-Based Protocols, Validation-Based Protocols) of Concurrency Control used in the database management system.
Multi version Concurrency Control and its applications in Advanced database s...GauthamSK4
Talks about the problems of concurrency and lock based mechanism and need for Multi Version Concurrency Control (MVCC).
PostgreSQL, application of MVCC.
Introduction to transaction processing concepts and theoryZainab Almugbel
Modified version of Chapter 21 of the book Fundamentals_of_Database_Systems,_6th_Edition with review questions
as part of database management system course
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
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Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Overview on Edible Vaccine: Pros & Cons with Mechanism
Multiversion Concurrency Control Techniques
1. Multiversion Concurrency Control Techniques
Q. What is multiversion concurrency control technique? Explain how
multiversion concurrency control can be achieved by using Time Stamp
Ordering.
To improve database performance, multiversion concurrency control protocols are developed to
extend the basic single version protocols. For single version databases, we have Two-phase
Locking, Timestamp Ordering and Optimistic Concurrency Control. Consequently. For
multiversion databases, there are Multiversion Two-phase Locking (MV2PL), Multiversion
Timestamp Ordering (MVTSO), and Multiversion Optimistic Concurrency Control.
The basic idea behind multiversion concurrency control is to maintain one or more old versions
(values) of data item when the item is updated.
When a transaction requires access to an item, an appropriate version is chosen to maintain the
serializability of the currently executing schedule, if possible. The idea is that some read
operations that would be rejected in other techniques can still be accepted by reading an older
version of the item to maintain serializability. When a transaction writes an item, it writes a new
version and the old version of the item is retained.
Disadvantages:
The drawback of multi version techniques is that more storage is needed to maintain multiple
versions of the database items.
Multiversion Technique Basedon Timestamp Ordering
In this method, several versions of each data item X are maintained. For each version, the value
of version and the following two timestamps are kept:
1. read_TS: The read timestamp of is the largest of all the timestamps of transactions that have
successfully read version .
2. write_TS: The write timestamp of is the timestamp of the transaction that wrote the value of
version .
Whenever a transaction T is allowed to execute a write_item(X) operation, a new version of item
X is created, with both the write_TS and the read_TS set to TS(T). Correspondingly, when a
transaction T is allowed to read the value of version Xi, the value of read_TS() is set to max(
read_TS() , TS(T)).
To ensure serializability, the following two rules are used:
1. If transaction T issues a write_item(X) operation, and version i of X has the highest write_TS()
of all versions of X that is also less than or equal to TS(T), and read_TS() > TS(T), then abort
2. and roll back transaction T; otherwise, create a new version of X with read_TS() = write_TS() =
TS(T).
2. If transaction T issues a read_item(X) operation, find the version i of X that has the highest
write_TS() of all versions of X that is also less than or equal to TS(T); then return the value of to
transaction T, and set the value of read_TS() to the larger of TS(T) and the current read_TS().
As we can see in case 2, a read_item(X) is always successful, since it finds the appropriate
version to read based on the write_TS of the various existing versions of X. In case 1, however,
transaction T may be aborted and rolled back. This happens if T is attempting to write a version
of X that should have been read by another transaction T whose timestamp is read_TS();
however, T has already read version Xi, which was written by the transaction with timestamp
equal to write_TS(). If this conflict occurs, T is rolled back; otherwise, a new version of X,
written by transaction T, is created.