What is the difference between a transaction file and a master file?
There is no fast rule to distinguish the two. In application programming, a file used to store transactions prior to posting to a summery for a general ledger, for example, would be called a transaction file. In application programming where data entry is separated from the main actors, that is, done by data entry operators rather than accounting clerks, then the transactions entered are stored in a transaction file and are subjected to manual and automated checks for accuracy before being committed to a master file. Some folk have a master file which is a golden copy of data and is subject to even more protections. But these terms are a bit out of date. Consider Oracle, PostgreSQL, or Zope Object Data Base. None need the distinction because all are ransactional. it is possible to undo anything that has been done to them with their own tools becayuse they store complete records of transactions. In fact, with postgres, the program pg_dump dumps every command that had an effect on the database into a big text file where psql can restore the entire database elsewhere. Zope Object database and Zope allow you to undo any one thing in the scope of records kept but the ZODB grows pretty fast so it is usually packed (losing its undo capability for a selectable number of days) at least monthly. That is someone issues a pack instruction for all transactions older than 30 days, for example. Combine that with regular backups, versioning systems, versioning filesystems, and so on, and the need for the transaction file/master file architecture is a diminishing one.
What are the ACID properties of database transactions?
Atomicity, Consistency, Isolation, DurabilityAtomicity is the property of a transaction to happen in total. For example, if I do a BEGIN TRANUpdate mytable set mycolumn = ‘mine’ where mytableID = 1;Insert into yourtable values ‘one’, ‘two’;COMMITThe database Atomic property guarantees that both statements will succed or NOT succed together.Consistency refers to the property of a database to only allow changes that are produced by using consistent and available methods. For example, you are only allowed to change or insert data using a language like SQL that the database understand and that follows the rules the database specify.Isolation refers to the database property that insures that each transaction executes as if there are no other transactions taking place. That is, if you and I execute a command that access the same object at exactly the same time, the database will decide which command gets to execute first and apply the changes sequentially. It will not allow your transaction to proceed some and then let mine proceed some.Durability refers to the database commitment to make sure that if a transaction commits the data changed, deleted or inserted will remain changed (whether it has been written to disk or not)The four properties are your guarantee that the database system will always behave in a reasonable manner and that all its actions can be traced.The database system will use locks (to prevent two transactions from accessing the same table at the same time), parse your commands to make sure that the syntax is correct, and, finally, the database will log all changes whether they happen in memory or on disk to make sure that the changes can be tracked and reapplied if necessary.
What is the use of ACID property in database management system?
ACID properties are 4 important properties of a transaction that a DBMS must ensure to maintain data in the case of concurrent access & system failures.These can explained by the working of an ATM machine.- Atomicity (all or nothing)Ex: Suppose you want to transfer Rs. 50 to your friend. Let your account be A & your friend's account be B. Let, Ti be a transaction that transfers Rs 50 from account A to B. Thus transaction can be defined as:Read (A,a)a:=a-50;Write (A,a)Read(B,b)b:=b+50;Write(B,b);Now, suppose values of A & B are 100 & 200 respectively. Suppose that during the execution of Ti, a power failure has occurred that prevented the Ti to complete successfully. The point of failure may be after the completion of Write(A,a) & before Write(B,b). It means that changes in A are performed but not in B.Thus the values of account A & B are Rs. 50 & 200 respectively.We have lost Rs. 50 as a result of this failure. Our database is in inconsistent state now, which is not a good sign.So, in order to get the consistent state , database must be restored to it's original values i.e 100 & 200 this leads to the concept of atomicity.In order to maintain the atomicity of a transaction , the database system keeps tracks of the old values of any write & if the transaction does not complete its execution, the old values are restored to make it appear as the transaction never executed.Similarly in rest of cases :-Consistency (no violation of integrity constants)- a database tracking a checking account may only allow unique check numbers to exist for each transaction-Isolation(concurrent changes invisble) - a teller looking up a balance must be isolated from a concurrent transaction involving a withdrawal from the same account. Only when the withdrawal transaction commits successfully and the teller looks at the balance again will the new balance be reported. -Durability(committed update persist) - A system crash or any other failure must not be allowed to lose the results of a transaction or the contents of the database. Durability is often achieved through separate transaction logs that can "re-create" all transactions from some picked point in time (like a backup).(Hope it helps, sorry I wrote it in a hurry)
What is a transaction and ACID properties in DBMS?
ACID PropertiesA transaction is a very small unit of a program and it may contain several lowlevel tasks. A transaction in a database system must maintain Atomicity, Consistency, Isolation, and Durability − commonly known as ACID properties − in order to ensure accuracy, completeness, and data integrity.Atomicity − This property states that a transaction must be treated as an atomic unit, that is, either all of its operations are executed or none. There must be no state in a database where a transaction is left partially completed. States should be defined either before the execution of the transaction or after the execution/abortion/failure of the transaction.Consistency − The database must remain in a consistent state after any transaction. No transaction should have any adverse effect on the data residing in the database. If the database was in a consistent state before the execution of a transaction, it must remain consistent after the execution of the transaction as well.Durability − The database should be durable enough to hold all its latest updates even if the system fails or restarts. If a transaction updates a chunk of data in a database and commits, then the database will hold the modified data. If a transaction commits but the system fails before the data could be written on to the disk, then that data will be updated once the system springs back into action.Isolation − In a database system where more than one transaction are being executed simultaneously and in parallel, the property of isolation states that all the transactions will be carried out and executed as if it is the only transaction in the system. No transaction will affect the existence of any other transaction.
What is the golden rule in accounting?
The types of accounts viz. real, nominal and personal have been explained in earlier articles. The golden rules of accounting require that you ascertain the type of account in question. Each account type has its rule that needs to be applied to account for the transactions. The golden rules have been listed below:The Golden Rules of AccountingDebit The Receiver, Credit The GiverThis principle is used in the case of personal accounts. When a person gives something to the organization, it becomes an inflow and therefore the person must be credit in the books of accounts. The converse of this is also true, which is why the receiver needs to be debited.Debit What Comes In, Credit What Goes OutThis principle is applied in case of real accounts. Real accounts involve machinery, land and building etc. They have a debit balance by default. Thus when you debit what comes in, you are adding to the existing account balance. This is exactly what needs to be done. Similarly when you credit what goes out, you are reducing the account balance when a tangible asset goes out of the organization.Debit All Expenses And Losses, Credit All Incomes And GainsThis rule is applied when the account in question is a nominal account. The capital of the company is a liability. Therefore it has a default credit balance. When you credit all incomes and gains, you increase the capital and by debiting expenses and losses, you decrease the capital. This is exactly what needs to be done for the system to stay in balance.The golden rules of accounting allow anyone to be a bookkeeper. They only need to understand the types of accounts and then diligently apply the rules.In ShortReal Accounting:Dr - What comes inCr - What goes outExamples of this kind of transaction include cash/bank and rent.Personal Accounting:Debit is the receiver.Credit is the giver.An example of this kind of transaction is Vendor/Customer relations.Nominal Accounting:All gains and income are credit.All losses and expenses are debit.An example of this kind of transaction is sales and/or purchases.
What if anything is done to control externalities?
The issue is that dogs are poor generalizers - it's not that the dog is "sneaky, greedy" etc, but that they have no intrinsic sense of morality or "rightness" and so only think something is "bad" if it has bad consequences. If it has never had bad consequences except with a human in the room, then how on earth are they to know that the rules still apply with the human out of the room? You need to train in such a way that corrections and rewards occur when the dog does not think you are present - i.e. hiding around the corner. Read here https://tr.im/chP70 I personally owned a Labrador Retriever (read: chow hound) that could be left 6" from a hot dog in a sit-stay for half an hour and not touch it - the word was "mine" and it meant that you don't touch that, even if I am not in the room, even if whatever, you DO NOT touch that. You could leave a plate of food on the floor for hours and not only would she not touch it, she would also keep the other animals (dogs and cats) from touching it. In all probability, these dogs studied were just not properly trained/proofed before the experiment. With "proofing" to set them up and catch them in the act to give
How can a teacher discipline in an out of control classroom?
what are we talking about? how out of control? is it a question of law enforcement? is it just talking? how in depth are we going here? There are many levels as to how things are to be done.... is there a ringleader? or is it a group? That person would be made an example of...I would make him/them do a huge paper that would represent the class. Each person that is involved in the scuffle must be represented in the paper or it won't get above 59%. Each person must submit his portion/chapter of the paper and the paper must be cohesive, lucid and clear. The score on the paper will be given to the whole class. In my opinion, a team must work as such and if the team is weak there is a reason and if they can work as a team again AND most important, LEARN from their errors, then they probably won't react in the same way again. Those with the best grades must delegate and cannot have direct input on the paper as they were NOT the ones responsible for the out of control behavior. I cannot however allow everyone to go unscathed. the class is a whole and must participate as a whole. They are responsible as young the young adults they "CLAIM" to be...we always hear how we don't give them their due credit...so..here you go...take the ball and run..as a group..as a class and as a team. You need to prove to me that you actually learned from your behavior and are actually capable to show that such behavior is justified by getting the best grade that you can. If you score extremely well, you will never see that done again. You obviously proved to me that you just needed a stress release. I CAN understand and even respect that, but you need to explaint to me in the paper better ways to go about it than to disrupt my class. By making even those with good GPAs involved...then the likelihood that this will happen again is very low. The good students will delegate and direct the paper even though they can only moderately get involved. They will not be held responsible for typing a portion of the paper as they will be more involved with the organization and the editing of the paper itself. The idea behind this is to teach and discipline and this accomplishes both.
Is it a violation of the 4th amendment ? To ban smoking in my apartment ? after 6 years which it was allowed?
Here's what it boils down to: you have the right to ruin your health (I, too, am a smoker and I WISH I could stop) but you do not have the right to endanger other people's health or right to health. It's very simple, loud noises at all hours of the day and night is not tolerate and there are no "Constitutional rights, freedoms and liberties" issues involved; neither is your smoking habits. You cannot impose YOUR habits on others. You're fighting an unpopular battle. Let me explain it this way, YOUR rights END where MY rights BEGIN. You have rights and so do the other tenants. This apt bldg prohibits smoking in elevators, stairwells all floor hallways and lobby areas. We have security surveillance cameras everywhere; some residents' kids have been caught on camera and reported to the parents with warnings of possible consequences (fines to dispossess). I'm a smoker and I obey them. Not because I submit but because it is the correct thing to do for the sake of others, including children and elderly.
Why are there rules and why is it so important to follow them?
Rules are important because they are guidelines to what is acceptable and what not. There would be no civilization without rules. In societies there has to be a guideline--something that regulates the conduct of people toward each other. Just think of it in smaller terms, in a family environment. Mother and Father establish rules by which children have to abide. For example, when parents tell their children that they cannot scream and yell at each other they are telling their children a (very important) rule. It regulates the behavior of the children--and so this is one factor why rules are important. The conduct between people in a society is better because of rules. Since the children from the above example learn not to scream and yell at each other do they in turn get along better with each other and not fight with each other. On a larger scale it creates the environment for a society in which screaming and yelling at each other is something that is not desirable, therefore people do keep their emotions in check and that in turn creates the same effect as with the children. People get along with each other. Another factor is the fact that rules also establish in a society what is considered a crime and what not. Even though some crimes are literally based on the 10 commandments, others ore based on established rules. For exmple, take the case where a older man has sex with a young teen, say she is 15, he is in his 30's. It is not acceptable in a society that has established the rule that sex between two people of such an age difference is not acceptable---and so this is made a law. The difference between a law and a rule is that the law describes what the rule is in a negative way, meaning it does state the terms of the broken rule as om "sex with a minor" and describes a proscribed penalty the breaker of the rule has to expect. Rules do establish a society: For example, Hammurabi, who to my knowledge formed the first society known established the rule that "the strong shall carry the weak". It was a rule of signifance, because this rule showed the responsibility of those who were strong. Without the rules we would be living in some sort of anarchy, a society where every one could just do what they wanted to without having to worry about consequences. Rules do establish a sense of accountability--to each other, to the neighbors, to the government--without rules we would only be a bunch of savages....