Interested to Buy Any Domain ? << Click Here >> for more details...
What is a transaction and what are ACID properties?
- 14 Answers
- 78025 Views
- Config Systems, IBM, TCS, Virtusa, I also Faced
- E-Mail Answers
Answer Posted / pardeep jangra
A transaction is a unit of program execution that
accesses and possibly updates various data items.
! A transaction must see a consistent database.
! During transaction execution the database may be
inconsistent.
! When the transaction is committed, the database must
be consistent.
ACID PROPERTIES
Atomicity- requires that each transaction is "all or
nothing": if one part of the transaction fails, the entire
transaction fails, and the database state is left unchanged.
An atomic system must guarantee atomicity in each and every
situation, including power failures, errors, and crashes.
Consistency
The consistency- property ensures that any transaction will
bring the database from one valid state to another. Any data
written to the database must be valid according to all
defined rules, including but not limited to constraints,
cascades, triggers, and any combination thereof.
Isolation
Isolation- property ensures that the concurrent execution of
transactions results in a system state that could have been
obtained if transactions are executed serially i.e. one
after the other.[citation needed]
Durability
Durability- means that once a transaction has been
committed, it will remain so, even in the event of power
loss, crashes, or errors. In a relational database, for
instance, once a group of SQL statements execute, the
results need to be stored permanently (even if the database
crashes immediately thereafter).
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
How to call a function from a stored procedure in SQL Server ?
Is the order of columns in the set clause important in ms sql server?
Explain filtered indexes benefits?
what is unique and xaml nonclustered index
how do you test proper tcp/ip configuration windows machine? : Sql server database administration
How to rebuild the master database?
How can you stop stored procedures from recompiling?
What is attribute hierarchy? : sql server analysis services, ssas
Write an SQL query to obtain the 2nd highest salary.
You accidentally delete the msdb database what effect does this have on your existing sql databases, and how do you recover?
Can sql server be linked with other servers like oracle?
What does it mean to invest in the index?
How to generate create table script on an existing table in ms sql server?
How to create prepared statements using odbc_prepare()?
What are triggers? How many triggers you can have on a table? How to invoke a trigger on demand?
