A database management system functions through the use of system commands, first receiving instructions from a database administrator in DBMS, then instructing the system accordingly, either to retrieve data, modify data, or load existing data from the system.
A relational database management system RDBMS refers to a collection of programs and capabilities that is designed to enable the user to create, update, and administer a relational database , which is characterized by its structuring of data into logically independent tables. Data is raw, unprocessed, unorganized facts that are seemingly random and do not yet carry any significance or meaning.
Information refers to data that has been organized, interpreted, and contextualized by a human or machine so that it possess relevance and purpose. Information is filtered data that has been made systematic and useful, and is considered to be more reliable and valuable to researchers as proper analysis and refinement has been conducted.
A DBMS is concerned with the manipulation of data in a database. A data model is an abstract model that organizes elements of data, documents the way data is stored and retrieved, standardizes how different data elements relate to one another and to the properties of real-world entities, and designs the responses needed for information system requirements.
There are three main types of DBMS data models: relational, network, and hierarchical. Other data models include entity-relationship, record base, object-oriented, object relation, semi-structured, associative, context, and flat data models.
Database system architecture in DBMS is categorized as either single tier, in which the DBMS is the only entity where the user directly sits on the DBMS and uses it, or multi-tier, in which nearly all components are independent and can be changed independently. A distributed database is a collection of related data in multiple interconnected databases that are logically interrelated, but physically stored across multiple physical locations. Distributed databases are categorized as either homogeneous, in which all the physical locations use the same hardware and run the same operating systems and applications, or heterogeneous, in which each location may have different data, software, and hardware structures.
Traditionally it was not possible where file-processing system was used. Applications of DBMS Database is a collection of related data and data is a collection of facts and figures that can be processed to produce information. Mostly data represents recordable facts. Data aids in producing information, which is based on facts. For example, if we have data about marks obtained by all students, we can then conclude about toppers and average marks. A database management system stores data in such a way that it becomes easier to retrieve, manipulate, and produce information.
Following are the important characteristics and applications of DBMS. These concepts are applied on transactions, which manipulate data in a database. ACID properties help the database stay healthy in multi-transactional environments and in case of failure. Though there are restrictions on transactions when users attempt to handle the same data item, but users are always unaware of them.
A user who is in the Sales department will have a different view of database than a person working in the Production department. This feature enables the users to have a concentrate view of the database according to their requirements. DBMS offers methods to impose constraints while entering data into the database and retrieving the same at a later stage. DBMS offers many different levels of security features, which enables multiple users to have different views with different features.
For example, a user in the Sales department cannot see the data that belongs to the Purchase department. Additionally, it can also be managed how much data of the Sales department should be displayed to the user. Since a DBMS is not saved on the disk as traditional file systems, it is very hard for miscreants to break the code.
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