A Database Management System or DBMS provides the interface between users and a database. Some of its tasks include: data integrity, security, recovery of data, support concurrent updates and update data.
several problems can occur when concurrent transaction execute in an uncontrolled manner.
Query processing can be divided into four main phases: decomposition, optimization, code generation, and execution.
Traditional FPS and DBMS both are different from each other. In DBMS there is security of data as well as integrated data while this is not in FPS.
if we need a modifying ,sreach,delete a file so we need a DBMS
Transaction
View Serializable is a correctness criterion in database management systems that ensures that the final result of executing concurrent transactions is the same as if they were executed one after the other. This property helps maintain data consistency and ensures that the database remains in a consistent state despite concurrent transaction execution. Transactions are said to be view serializable if their interleaved execution produces the same results as if they were executed sequentially.
The three most common concurrent transaction executive problems are uncommitted data, lost updates, and inconsistent retrievals. It is believed that concurrency control can help these problems.
How do you start and finish a transaction in DBMS?
MySQL is an RDBMS.
any change in database is called transaction.
Primarily it's based on rules about when changes to data are posted in a transaction and read by other users, which are part of the record-locking features of the DBMS. Some DBMS's manage this with undo and redo logs, which support snapshotting the data before the updates were started, so that other users can access the records before the update transaction was started.
Transactions' Importance:Users can submit transaction and can think of each transaction as executing by itself.A transaction might commit after completing all its actions, or it could abort(or be aborted by the DBMS) after executing some actions.
several problems can occur when concurrent transaction execute in an uncontrolled manner.
transaction
the ability to enforce mutual exclusion
data dictionary and transaction log