Services
of DBMS:
There
are the following important services provided by a DBMS:
1.
Transaction Management:
A transaction is a series of database
operations, carried out by a single user or application program, which accesses
or changes the contents of the database. Therefore, a DBMS must provide a
mechanism to ensure either that all the updates corresponding to a given
transaction are made or that none of them is made.
2.
Concurrency Control:
Since DBMSs support sharing of data
among multiple users, they must provide a mechanism for managing concurrent
access to the database. DBMSs ensure that the database kept in consistent state
and that integrity of the data is preserved.
3.
Recovery Management:
The DBMS provides mechanisms for
backing up data periodically and recovering from different types of failures.
This prevents the loss of data.
4.
Security Management:
The DBMS protects the database against
unauthorized access, either international or accidental. It furnishes mechanism
to ensure that only authorized users an access the database.
5.
Language Interface:
All DBMS provide interface to enable
applications to use DBMS services. They provide data access via Structured
Query Language (SQL). The DBMS query language contains two components: (a) a
Data Definition Language (DDL) and (b) a Data Manipulation Language (DML).
6.
Storage Management:
It provides a mechanism for management
of permanent storage of the data. The internal schema defines how the data
should be stored by the storage management mechanism and the storage manager
interfaces with the operating system to access the physical storage.
7.
Data Catalog Management:
The DBMS provides a data dictionary or system
catalog function in which descriptions of data items are stored and which is
accessible to users.
No comments:
Post a Comment