In this article database schema in DBMS we give the information about Schema in a DBMS describes the structure of data in the database and defines its elements in an organized manner.
Schema in a DBMS:-
Schema in a DBMS describes the structure of data in the database and defines its elements in an organized manner. It decides which tables will be in the database, what columns they will contain, and how the type and organization of data in these columns will be presented.
Schema is important in the design of a database, as it helps in keeping the data organized and managing it properly. Without this, data added to the database may be ineffective.
Its have four main purposes:
- Data Structure: The structure of data is presented in a special way by a schema database. Here data is organized through tables, columns, and relationships between them.
- Data Request and Processing: Schema helps in understanding and processing data requests by structuring the data defined in the database.
- Data Optimization: By schema database, validity, invalidity and optimization of data can be followed in a structured manner. This helps ensure the correctness and reliability of the data.
- Data Security: Schema promotes database security, as it establishes controls and identities that protect data from unauthorized access.
Schema databases are used for data modeling, arranging data, and modifying data so that data can be managed in an organized and effective manner.
Subschema in DBMS:-
Subschema refers to attributes or sections used in a database that allow users to view and access the database from different perspectives. This subschema is useful for limiting or managing access to data for different users or user groups. Subschema is used to manage security and permissions in the database.
“Subschema” are used to handle multiple levels of organization and security in a database management system (DBMS). It is a set of permissions and features that allow users to access and administer various parts of the database. These are set by administrators to grant different levels of access to different types of users.
The subschema creates the interface between the administrator and the user. Administrators define subschema that allow users to access data as per their needs and permissions. This system allows users to access only the information necessary for their work and hides all other information. Thus, subschema promotes security and help manage permissions, as well as control access to data at various levels.