Purpose
Databases and other data stores which treat the integrity of data as paramount often include the ability to handle transactions to maintain the integrity of data. A single transaction consists of one or more independent units of work, each reading and/or writing information to a database or other data store. When this happens it is often important to ensure that all such processing leaves the database or data store in a consistent state.
Examples from double-entry accounting systems often illustrate the concept of transactions. In double-entry accounting every debit requires the recording of an associated credit. If one writes a check for €100 to buy groceries, a transactional double-entry accounting system must record the following two entries to cover the single transaction:
- Debit €100 to Groceries Expense Account
- Credit €100 to Checking Account
A transactional system would make both entries pass or both entries would fail. By treating the recording of multiple entries as an atomic transactional unit of work the system maintains the integrity of the data recorded. In other words, nobody ends up with a situation in which a debit is recorded but no associated credit is recorded, or vice versa.
Read more about this topic: Database Transaction
Famous quotes containing the word purpose:
“I have always felt that the real purpose of government is to enhance the lives of people and that a leader can best do that by restraining government in most cases instead of enlarging it at every opportunity.”
—Gerald R. Ford (b. 1913)
“Science and art, or by the same token, poetry and prose differ from one another like a journey and an excursion. The purpose of the journey is its goal, the purpose of an excursion is the process.”
—Franz Grillparzer (1791–1872)
“Your good mother tells me you are feeling very badly in your new situation. Allow me to assure you it is a perfect certainty that you will, very soon, feel better—quite happy—if you only stick to the resolution you have taken to procure a military education. I am older than you, have felt badly myself, and know, what I tell you is true. Adhere to your purpose and you will soon feel as well as you ever did.”
—Abraham Lincoln (1809–1865)