What are the 4 features of database?
A major feature of a database system is to provide users with an abstract view of data i.e. the system hides certain details of how data is stored and maintained. Show 1) Data AbstractionData abstraction is the property of showing only the necessary details to a user and hides the rest of the details from that user. Since many database system users are not computer trained, developers hide the complexity from users through several levels of abstraction, to simplify user’s interactions with the system.
The inter-relationship between the three levels is as shown below: 2) Instances and SchemasDatabases change over time as information is inserted and deleted. The collection of information stored in the database at a particular moment of time is called an instance of the database. The overall design of the database is called the database schema. Schemas are not expected to change frequently. 3) Data independenceThe ability to modify a schema definition in one level without affecting the schema definition in the next higher level is called data independence. There are two levels of data independence. a) Physical data independence – It is the ability to change the physical schema without changing the logical schema. Modifications at the physical level are occasionally necessary to improve performance. b) Logical data independence – It is the ability to modify the logical schema without changing the schema at the view level. Modifications at the logical level are necessary whenever the logical structure of the database is altered. The concept of Keys in database:A relation is defined as a set of tuples. By definition, all elements of a set are distinct; hence, all tuples in a relation must also be distinct. This means that no two tuples can have the same combination of values for all their attributes. The various keys used in databses are:
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What are the four features of database?Features Of DataBase Management Systems (DBMS):. Minimum Redundancy and Duplication. ... . Reduced amount of space and money spent on storage. ... . Data Organization. ... . Customization of the Database. ... . Data Retrieval. ... . Usage Of Query Languages. ... . Multi User Access. ... . Data Integrity is Maintained.. What are the main features of a database?Features of Database Management System (DBMS). Minimum Duplication and Redundancy.. Saves Storage Space and Cost.. Anyone Can Work on It.. Large Database Maintenance.. Provides High Level of Security.. Permanent Storage of Data.. What are 4 types of database?A relational database management system is one of four common types of systems you can use to manage your business data.. hierarchical database systems.. network database systems.. object-oriented database systems.. What is database system what are its features?A database supports multiple views of data. A view is a subset of the database, which is defined and dedicated for particular users of the system. Multiple users in the system might have different views of the system. Each view might contain only the data of interest to a user or group of users.
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