Dbms

 What is Dbms ?

i Srands for database management system, its main purpose revolves around the Data

 this system allows its user to store the data, define it , retrieve it and also update the information about the data inside the database.

Two types of DBMS:

RDMS- mysql

NOSql-mongodb(json) and neo4j(graph)

it is a collection of data in a organized way such that it can to facilitate its users to easily access, manage and upload data 

Dbms were developed to handle the following problems of the traditional file- processing system supported by conventional OS:

1. data redundancy and inconsistency 
2. Easy access to data 
3. Security 
4. atomicity durability isolartion and consistency- not present  
5. consurrent access by doffernt users - one by one 

this is a problem que when the interviewer will ask about the databse used by you and asks if you made aER diagram before making the entities

steps:

entity set 

attributes

relatins

all the rows or entries together forms a set and this set is called the entity set 

table level constraint here is foreign key 

what are the diff types of keys and explain