40-50 % comes from Database
Just cram all these points can come in exam. 9th feb 2014 and further ibps bank exam
1- database collection of inter related data
goal – to store and retrieve conveniently and efficiently
2- Components of database system
Data, hardware,software, users
No data redundancy, data is consistent, easy access, no data isolation ,multiple users can access, secure, maintain integrity.
4- data abstraction is at view level
5- there are 3 levels lowest physical level- how data are stored , it is complex
Middle conceptual level what data is stored, relationship among data
Then the top level view level describe part of database,highest level.
6- very important ER Model
Entity relationship model consists of entity and attributes, relationships
Ellipses shows attributes, rectangle is entity, lines tell relationship between entity and attributes.
7- data models are of 3 types record based logical model, physical model, object based.
ER Model is object based model.
Important question what is cardinality- its degree .
Ask if there is any doubt happy to help you !