Technical Education ARKujur

Definition are Network, Hierarchical and entity -relationship model Network Model:- The network Model data are represented by collection of records and relationships among data are represented by links. Advantages of network Model:- Simplicity:-  The network Model is also conceptually simple and easy to design. Ability to handle more relationship type:-  The network Model can handle the one to many and many to many relationships. Easy of data access:-  Relationship is a set comprises of two type of records an owner record and a member record. Data integrity:-  In a network model no member can exist without an owner. A user must therefore first define the owner record and then the member record. Data independence:-  The network Model draws a clear line of demarcation between the programs and the complex physical storage details. Database standard:-  The standard devised by the DBTG (database Task Group of CODASYL Commtiee)form the basis of the network Model....

Write ✍️✍️✍️ a Query processing and transaction processing   Query Processing:-  The technique used by a DBMS to process ,optimize,and execute high level queries.An internal representation of the query is then created, usually as a tree data structure called a query tree. The query can also be represented using a graph data structure called a query graph.             A query typically has many possible execution strategies and the process of selecting an appropriate one for processing a query is known as query optimization.    Transaction processing:- A transaction can be considered as a unit of program execution that access and update various data items of a database. A transaction can be regarded as a series of reads writes of data objects. This processing are following properties of the transaction:- Atomicity:-   Either all the operation of a transaction are carried out or none are. User need not worry about the effect of i...