Composite attribute in dbms
Database Management System SoS in Computer Science and Application PGDCA 203 : DBMS Presented By Shruti Dubey. Why we have Keys in DB? •A Key is an attribute or a set of attributes in a relation that identifies a tuple (record) in a relation. ... Composite Key •If a table do ...For some relations, changing the data can have undesirable consequences called: In the __________ normal form, a composite attribute is converted to individual attributes. The rule which states that set of attributes determines any of its subset is classified as. Every Boyee-Codd normal form is in.
Domain: set of values for an attribute. Types of Attribute: 1. Simple and Composite attribute: Simple attribute cannot be divider furthered. It is represented by oval. e.g. Roll_No, Id, DOB, first name, city etc. Composite attribute can be divided furthered. In this one oval can be connected by many ovals.Complex Attribute. complex Attribute is a type of attribute in database. It is formed by nesting composite attributes and multi-valued attributes in arbitrary way. We can say this as the both are in the attribute. For example, A person can have many phone numbers,many e-mail addresses,home addresses etc.So if there is a attribute in the name of ...Partial, Unique, Secondary, Composite and Surrogate keys in DBMS. The set of attributes that are used to uniquely identify a weak entity set is called the Partial key. Only a bunch of the tuples can be identified using the partial keys. The partial Key of the weak entity set is also known as a discriminator. It is just a part of the key as only ...Domain – the set of permitted values for each attribute Attribute types: Simple and composite attributes. Single -valuedand multi attributes E.g. multivalued attribute: phone-numbers Derived attributes Can be computed from other attributes E.g. age, given date of birth Database System Concepts 2.4 ©Silberschatz, Korth and Sudarshan
31. Answer : (b) Reason : DBMS mainly focuses on the proper generation, storage, and retrieval of data. 32. Answer : (a) Reason : Query language is used to interact with the database. 33. Answer : (d) Reason: Relational data base helps us to design the data base in a easier manner.