What is the difference between Transaction and a Query?

Question

Below is the one of the interview question which was held by Oracle

If a transaction is very large, and the rollback segment is not able to hold the rollback information, then will the transaction span across different rollback segments or will it terminate?

Answer 1

A query is a single statement in SQL's data manipulation language: typically one of SELECT, INSERT, UPDATE or DELETE (the latter three may modify data, while SELECT only reads data).

A transaction is a group of statements which taken together, are usually defined to have "ACID" semantics (my own off the cuff definitions are below, but these are defined in any web or paper reference to relational database):

• Atomicity (all statements in the transaction are executed, or none)

• Consistency (the database is never viewable in an inconsistent state)

• Isolation (a transaction does not affect other transactions)

• List item Durable (once committed, the changes in the transaction are permanent)