Multidatabase Query Processing, Introduction to Transaction Management, Distributed Concurrency Control, Distributed DBMS Reliability Essay Example

Multidatabase Query Processing, Introduction to Transaction Management, Distributed Concurrency Control, Distributed DBMS Reliability Essay Introduction to Transaction Management Name: Course: Lecturer: We will write a custom essay sample on Multidatabase Query Processing, Introduction to Transaction Management, Distributed Concurrency Control, Distributed DBMS Reliability specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Multidatabase Query Processing, Introduction to Transaction Management, Distributed Concurrency Control, Distributed DBMS Reliability specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Multidatabase Query Processing, Introduction to Transaction Management, Distributed Concurrency Control, Distributed DBMS Reliability specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Date: Introduction to Transaction Management A transaction is a sequence of operations of the database that are organized in a basic unit where databases are kept reliable and consistent. A database is said to be consistent when it has the following features; it has referential integrity, it maintains entity integrity and if it remains within the constraints set by the domain values. Moreover, a database should remain consistent before the execution of a transaction and after. During the execution of a transaction, a database should be in an inconsistent state where no other transaction should be exposed to it. Regardless of the number of transactions accessing the database, it should always remain in a consistent state[1]. The reliability of a database is determined by its capability to recover and its resiliency. A transaction is a sequence of operations involving the commands of reading and writing on a database. For instance an SQL statement is regarded as a transaction, a program that is enclosed by the commands ‘Begin-transaction’ and ‘end’ is also a transaction. A transaction can be terminated by commands of committing it or rolling it back. If a transaction is committed, it has been successfully completed and if it is rolled back, it has been aborted. The commit command makes the effect of the operations of the database permanent and the results can be viewed by all other transactions. The rollback command on the other hand has the effect of undoing the operations and restoring the database to the state it was before the transaction was executed[2]. Transactions can fail to complete for three reasons. They could be aborted by the management system, either if the system crashes or if the transaction aborts itself. When this occurs, the effects of the transaction should be undone. This helps the user to forget about the undone transaction as it has already been taken care of. However, if a transaction is completed it should be durable and its effects should last. The database management system log ensures the undoing of incomplete transactions where necessary. A database must ensure that four very important qualities of a transaction are fulfilled. These are atomicity, consistency, isolation and durability. All transactions should be atomic, meaning that they are supposed to either happen or not. All transactions should run by themselves and should be consistent. By default, the database management system assumes that the transactions are consistent. Transactions should be isolated from the effects of other transactions that are executable concurrently. The effects of the transaction should be consistent once the user is notified of their success even in the event of the crashing of the system. A user is usually responsible for the consistency of their transaction. If a database is in a consistent state when the transaction is beginning, the database should remain in the same state after the transaction is over. The management system for the database does the work of enforcing the commands and other constraints that the transactions should operate on. Every transaction sees the database as consistent. The user issues commands that prompt transactions and assume that each transaction shall be executed by itself; however, the management system of the database arranges the actions to be performed concurrently. The total effect shows the user that the many transactions that they have tasked the system to perform have been executed one after the other[3]. Since transactions are seen as series of read and write commands by the management system, a list of actions is developed. The management system also specifies if the transaction is to be committed or aborted. A schedule is created by the management system for transactions. The schedule is a list of actions, whether read, commit, write or abort that are attributed to a set of transactions. The order in which they happen in the schedule is similar to how they occur in the transaction. The schedule is also seen as an execution sequence of a set of transactions. The schedule describes actions as they are seen by the management system. Transactions are of different types and can be classified according to different classifications. By applications, transactions can be regular or distributed transactions. The transactions can also be compensating or heterogeneous. A compensating transaction has the purpose of undoing the effects of previous transactions. A heterogeneous transaction on the other hand has the runs in a heterogeneous database. By duration, transactions can be classified as short-life or on-line transactions or as Batch or long-life transactions. By structure, there are nested transactions and traditional flat structured transactions[4]. There are other types of transactions, for instance, a sub-transaction is a transaction that must begin after its parent transaction and end before its parent transaction. This means that the commit or abort command of this kind of transaction depends on its parent. The sub-transactions that exist within one parent are executable in parallel. The sub transactions have a special feature of recovering from failures independently without affecting the rest of the database and other transactions. Bibliography Chorafas, Dimitris. Transaction management: managing complex transactions and sharing distributed databases. New York, NY: Palgrave Macmillan, 1998. Gray, Jim and Andreas Reuter. Transaction processing: concepts and techniques. New York, NY: Morgan Kaufmann, 1993. Ozsu, Tamer, and Patrick Valduriez. Principles of Distributed Database Systems. New York, NY: Springer, 2011. Saake, Gunter and Kerstin Schwarz. Transactions and database dynamics. New York, NY: Springer, 2000. [1] Dimitris Chorafas, Transaction management: managing complex transactions and sharing distributed databases (New York, NY: Palgrave Macmillan, 1998), 98.

Oedipus the King Essay Example

Oedipus the King Essay Example Oedipus the King Essay Oedipus the King Essay When given a prophecy, most accept it and live their lives accordingly. From day one everyone did all possible to prove Oedipus’s prophesy wrong, and did all possible to prevent it. Oedipus left his family in route for a new fresh life. Oedipus was naive in disregarding his prophecy, proving that the human race is sheltered from what they see and what they chose to believe. Despite knowing of his prophecy since birth, Oedipus lives his life naive of his foreshadowed destiny. Though countless hints and warnings, Oedipus continues to see past the truth of his prophecy, and only believes what benefits him directly. Oedipus summoned Teiresia to come to Thebes, to help Oedipus solve the mystery of Laius, but ends up setting himself up for his own demise. Teiresia tries to evade telling Oedipus who was responsible, but found himself unable. Though Oedipus knew of his fate and was being told of his past, he still was horrified that someone could accuse him of such a crime. Oedipus was unable to see the reality of this situation; instead he created his own fantasy about prevailing situation. By moving away from his, or what he though was his, family, Oedipus thought he was debunking his prophecy and fate. Feeling so mighty in saving the city and dodging his fate, Oedipus actually made himself small and blind and imperceptive, to what a real man would see and accept. But by, attempting to prove his innocence he actually bought about his own fall. Jocasta to gives Oedipus hints to his true past, but because he is unable to comprehend anything but his idea of the truth, he continues his search of the murderer. Oedipus brings on his own demise by being blinded to what everyone is clearly drawing for him. He is not ready to accept fate or his role in the murder, for he is still in a sense blind to reality. Oedipus, fearing he has murdered a king and his own father, suddenly begins to put the puzzle pieces together, revealing that he indeed murdered his father, Laius. Gorging his eyeballs out and blinding himself was the only way for Oedipus to have a clear vision of reality. Oedipus could not grasp sleeping with his wife and mother, fathering his children and siblings, and murdering his father and king; therefore he had to abandon his resurrected â€Å"life†. Oedipus begged Creon to â€Å"Get rid of me quickly. Deport me To some empty waste land†¦Ã¢â‚¬  Finally excepting his fate, Oedipus wants to go into the mountains where he can die, as he was supposed to do. By blinding himself to the truth for so long, he made it impossible for Jocasta to live, and his children to live normally. By being naive to his fate, Oedipus not only found his demise but compromised the life of the three closest to him. This shows the human race’s refusal to believe anything that would hinder there well being. Oedipus felt superior to the gods, to the oracles, and to fate leading to him overall failure. By being blind, to all that is not rationally seen, we close our minds to the world. Oedipus lived his life closed minded to any thought other than his successful avoidance of his prophecy, therefore missing all the clues that led him straight to it. When we close our minds to anything out of the ordinary, or any thought unlike the desired belief, we create a jaded and fictional reality. If Oedipus had initially accepted his fate, or listened to the truth of Laius’s death, he would have saved the life of his wife and the humility of his two children. Being naive to what is destined to happen causes Oedipus to be blind to what was made very obvious to him. Ironically, he needed to be blinded to see and understand what was so clearly drawn out in front of him.

Describe the tradeoffs of business in a borderless world Assignment

Describe the tradeoffs of business in a borderless world - Assignment Example e need of social interaction, giving low consideration to the slow rate of revenue generation plus the fact that competition is getting far more serious. This situation is what we may call as an unsatisfactory compromise, a business tradeoff, as we may commonly call it. Cambridge International Dictionary of English explains â€Å"trade-off† as â€Å"a balancing of two opposing situations or qualities, both of which are desired. There is a trade-off between doing the job accurately and doing it quickly†¦A trade-off is also something that you do not really want but you accept, in order to have something else that you do want.† (Cambridge International Dictionary of English) In the world of business decision-making, tradeoffs are essential and vital. Applying the same to social networking sites, such as Twitter, tradeoffs play an important role in major business decisions wherein it calls for the need of monetizing its business and generative revenues without sacrific ing the infectious attraction and ease of its features of microblogging. A borderless world signifies a global integration of world economies. A network of partnerships, collaborative joint ventures, business relationships and alliances are formed giving rise to diffusion of new technology and a more open world economy. In a speech given by Everett M. Ehrlich, he envisioned a global marketplace – a borderless economy – wherein epochal information technologies have disintegrated our firms and led to a restructuring of the economic market. (Ehrlich, 2007) What once was an economic setup once barred with walls preventing the sharing of information and strategic solutions is now a solely integrated and symbiotic venture where an exchange of fast and accessible information through various open networks facilitate distribution and action leading to wise business decision-making. In other words, modern companies now demand the highest level of competitiveness in every activity, rather than introducing new

Criminal Justice System Essay Example | Topics and Well Written Essays - 500 words

Criminal Justice System - Essay Example Otherwise, the people would lose confidence in their capacity to protect the people and keep them safe. The most insistent factors that must be considered in the case given are first, the protocol of the police station or simply the rules that they must follow, second, the rights of the suspects and third, upholding justice for the victim. It may seem that all these are very distinct and therefore uncorrelated at first glimpse, but a thorough study will show that they are very much consistent with each other. Given the situation, what I would probably do is to insist to my partner that we redo the interview with me in the room and the same being videotaped. I would make an effort to notify accordingly that affirmative action must be done. This would assert a number of the major things that must be considered in an ethical decision. It would not be far fetch to consider that the confession was coerced. Not to mention that both are minors aged only at 14 years old. â€Å"The ethical t reatment of others requires that we treat them as rational agents who are authors of their own decisions, and not as tools that we may use or manipulate as we like† (Kleinig, 2008). It is by duty that I uphold that justice is served. The mandate for interviews was established for a reason.

Chevy Silverado advertisement, Essay Example | Topics and Well Written Essays - 500 words

Chevy Silverado advertisement, - Essay Example Luther king Jnr in the commercial as the theme song progresses with the words â€Å"I believe there is a dream for everyone† is aimed at provoking the mind of the potential customer that the Silverado is their dream car. It is also a car for the entire American population; black or white. The use of the images of Armstrong on the moon shows it can be viewed as a truck of prestige. The landing of man on the moon was a prestigious occasion for America. The technology involved in doing it could also suggest that the Chevy is a technologically advanced truck. There are images of the hurricane’s devastating effects with an older make of the Chevy being used for the reconstruction. This portrays the Chevy brand as reliable trucks. The three historical events have all brought the American people together. It could be in different fronts but their happening has brought a sense of unity to the country. The Martin Luther King brought the fight for civil rights and won the fight against racial segregation. This united the American races. The landing on the moon for the first time also brought Americans together in pride. The hurricanes that have devastated the people of America have also seen the country unite in agony and gloom. The larger picture is that the car is a unifying factor. They show the Silverado as a car with rich history and indispensible value. Chevy has used these events in their commercial effectively but not accurately. If the events were to compel the buyers, they should have had more emphasis laid on them. The events should have been played slowly. The commercial is very fast paced and has a very busy theme with so many clips flashing by. However, the average American should understand the context. Apart from the used historical events, Chevy could have considered the use of the bombing of the W.T.O. It would have portrayed the vehicle as a strong truck against the background of the falling houses. This would not be any different from the Hurricane

Debate Of Whether Psychology Is A Science

Debate Of Whether Psychology Is A Science Empiricism and Positivism are the two major philosophical influences on psychology; the empiricists brought the concept that all ideas are derived from experience. Experience is the basis of all knowledge. And the positivists further explained that sensory experience which can be shared with others can be objectively studied by observing their overt behavior. Determinism, indeterminism and nondeterminism hold different view on whether psychology is a science. Some aspects of psychology are scientific and some are not. Behaviorist, for example, used scientific method to understand human, while humanists do not used this kind of methodology. It is clearly that psychology is not a pure science instead it scientifically studies the nature of human and animals. Introduction In trying to answer the important and complex question of whether psychology is a science, we will first take a brief look at two major philosophical influences that help to create psychology- Empiricism and Positivism. Then study the view of determinism, indeterminism and nondeterminism of different psychologists to discuss the mind and subject matter of psychology. And finally, try to compare determinism and free will and conclude writers view on this original question Is psychology a science?. Empiricism John Locke, David Hume and David Hartley etc were the British empiricists who stressed that the important of experience in the attainment of knowledge. And the only source of true knowledge about the world is sensory experience which is information that comes to our senses or our inferences between the relationships of sensory facts. The word empirical is often used with the concept of science which implies that science used observation, measurement of the world and collecting data in the environment. This view is contrast with the Rationalists who believed that knowledge is innate and inborn. Locke maintained that the mind at birth was purely nothing, but experiences color it. This idea built into the behaviorist view of learning, like children can be made into anything that environment want it to be. The implication of empiricism on psychology include, firstly, the idea of conscious mind into simple ideas or overt behavior into stimuli response behavior and secondly, provided us the theory of association for explaining how simple elements can be combined to form complex elements or compounds. Thus the empiricist provided for psychology both a theory and methodology that most behaviorists made used of and is still influence todays psychology. Positivism Comte, the positivist, claimed that the only things we can be sure of is thing that can publicly observable. That is, sense experience that can be shared with other people. The data of science is observable and therefore can be trusted and only scientific information can be considered valid. Anything that is not publicly observable is suspect and is rejected because it is not a proper object to study. He did not believe psychology could not become a science because the only way to study the mind is using unreliable method of introspection. To study individual, it can be objectively studied by observing their overt behavior or through phrenological analysis. There are two significant impact of positivism on psychology: firstly, Darwins evolution theory enabled psychology to be placed in field of biological science. Secondly, psychology can be treated experimentally under Wundts psychology laboratory. Determinism All determinists believe that all behavior is caused and there are three kinds of determinism: the first one is biological determinism which emphasizes that behavior can be caused by physiological conditions or genetic predisposition, for example, mental illness was caused because of the lack of neurotransmitter, dopamine, in the brain. And that people will suffer abnormal behavior. Most human behavior is genetically inherited. The second one is environmental determinism, stressed that the environmental stimulus as the determinants of human behavior. For example, behavior theory emphasizes that environmental stimulus determine our behavior. The third determinism is sociocultural determinism, it is a form of environmental determinism, but emphasizes on the cultural factors like rules, regulations and beliefs that govern human behavior. For example, everyone keep quite in the library automatically because the social norm of our culture is no talking in the library. So, the environment factor guides our behaviors. Freud and Skinner, who are both determinists, agreed with the view that human behavior is caused. The neo-behaviorist B. F. Skinner held the view that the person is not free. In his book Beyond freedom and Dignity (1971), he argues that behavioral freedom is an illusion. His famous concept of operant conditioning, suggested that when negative reinforcers are consider along with rewards, then almost all behavior is controlled by association of reinforcement which occur constantly in the environment. What we think that we are behaving freely is not accurate because we are merely free of negative reinforcement or its threat; our behavior is still determined by the pursuit of things that have been positively reinforcing in the past, and consists of responses that have previously been positively reinforced. When we perceive others as behaving freely we are merely unaware of their reinforcement histories and the association that govern their behavior. So, Skinner concluded that behavioral freedom is an illusion. Other determinist, Freud, also rejects the possibility of free will. Every cause of humans behavior comes from within the individuals own unconscious mind; for Skinners view, they are external. However, from the view of inductive nature of science, it is clear that total predictability is impossible. The past does not logically predict the future, if it is true for physics, does it still true for human behavior? And how much more true it is? So if the main requirement of determinism is that behavior should be completely predictable, it does not seem to bring the same reason to the free will view after all. Indeterminism Some psychologists believe that human behavior is determined but since the universe is complex, we cannot accurately measure all the cause of our behavior. As Heisnberg said, despite human behavior is determined, we cannot know at least some of causes of behavior because we change that behavior when we are attempting to observe them. Psychologists who accepted this view believing that there are some specific causes of behavior but that we cannot accurately known. For example, when studying humans thought and behavior, just like social psychologists does in their experiment; one dependent variable can be caused by many independent variables. The problem of youngsters drug abuse can be caused by peer influence, family problem, personal attitudes or others factors. The drug abuse behavior is determined, but we cannot accurately measure or discover all the causes. Determinism versus Nondeterminism (Free will) Our everyday common sense understanding is that people have the ability to choose their own course of action, to determine their lives and, to this extent, have free will. Free will could be exercised within physical, political, environmental and other sociological factors. Sometimes, when we think about the concept of free will, it is also linked to the concept of responsibility; we normally think that people are responsible for what they do since they are the cause of what they do, that is they are not driven by any outsides factors. Most humanists or existentialists, like Carl Rogers, Rollo May and George Kelly etc assume that human behaviors are freely chosen and therefore cannot be tested by scientific method. This belief in free will is contrary to the view of determinism. Therefore, these psychologists are considered nonscientific. These psychologists are strongly influenced by the concept that our nature of experience and our knowledge of the external world are determined on how we interpret and define it. The universe is occupied only by the minds, and physical objects depend on and exist in individuals mind. But the view of positivism in the nature of scientific psychology is different. They imply that behavior is determined by external events or stimuli and that people response to it passively and, to this extent, are not free. Determinism also implies that behavior is totally predictable, as they occur in a regular, orderly manner. And every human action has a cause. An important distinction can be made between compulsion on the one hand and determinism on the other hand. Free actions are free from compulsion, but this is consistent with them being determined. The view which William James proposed called soft determinism. He argued that the question of free action is depending on the type of cause our behavior has. If our actions have as their proximate cause something like conscious mind, we can see them as free, rational, voluntary, purposive actions. Is psychology a science? Is psychology science? Some aspects of psychology are scientific and some are not. The psychologist used scientific method have provided very much useful information in every major area of psychology, for example, memory, personality, learning, perception, intelligence, motivation and psychotherapy. Structuralism, behaviorism and cognitive psychology used scientific method to study the nature of human being. In structuralism, psychologists try to identify the elements of the humans conscious thoughts and feelings. Then, its work is replaced by behaviorism which its emphasis on the objective observation of the behaviors of adults, children and animals. While cognitive psychologists recognize that cognitive process can be inferred from observable behavior and be studied under experimental setting. And these three aspects have a clear definition of subject-matter, a fundamental assumption of learning, it allows prediction and control and it is a methodology, with the controlled experiment. Psychology cannot be concluded as a totally science, some even said that psychology is rather a pseudo-science or it is still in a pre-scientific stage. Since some aspects of psychology, for example the subjective mind cannot be tested scientifically as it can change from time to time. When answering the question Is psychology a science? It can be concluded that psychology is not a normal science. Whether or not we consider psychology as a science depend on which aspect of psychology we are focusing on. Clearly that not all psychologists are methodological, for example, psychoanalytic and humanistic psychologists. If we change the question to Is psychology science? It is surely answered that psychology is scientific. Conclusion

Superstitious :: Free Essay Writer

Superstitious R.L. Stine who is one of America’s best-selling authors and the devilish creator of the Fear Street and Goosebumps series of horror stories for kids. Stine is who wrote the book I read, but he came back with a book for the older generation. All of Stines ideas in his books are suggested from real life. Most of his ideas came from his imagination and his memory. He now lives in New York City with his wife Jane, and teenage son, Matthew. The story took place on a small Pennsylvania College campus. Numerous of murders had taken place. Every murder was much more gruesome than the first. The detectives didn't know what had happened. The victims looked like an out of control animal rather than a human killed them. One of the main characters in this was Sara Morgan. She had just moved to Pennsylvania or school. Everything was going just fine until she met a professor named Liam O'Connor; he was another main character. Liam had a dashing romantic figure with a Irish accent, good looks, sweet charm, and a host of Old World superstitious-all of which dazzled Sara. Plunging headlong into a sudden love affair, Sara barely had time to notice the horrible events taking place on the campus. Liam was extremely close to his sister Margaret. A little too close that is. Sara and Liam soon got married after a couple of dates. Everyone said it was strange, yet, too soon for him or her. But she claimed she was in love with him. She started receiving crank phone calls, warning her to stay away from Liam. Then she received two bloody rabbit feet in the mail saying " If you’re going to marry Liam, you’re gonna need all the luck you can get." That scared her to death. When she told Liam about it, he acted like he didn’t care. Instead he blew all up in her face because she left out the front door and came in through the back door. Lately his superstitions had been getting out of hand. And he had been getting real mad at Sara. On their wedding night they made love by the light of sixteen candles, which was one of his superstitions. They were going on, non-stop. Then he whispered in her ear that he wanted to impregnate her. She accepted the offer without really thinking.