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 Dynamic Programming -  Dynamic programming approach is similar to divide and conquer in breaking down the problem into smaller and yet smaller possible sub-problems. But unlike, divide and conquer, these sub-problems are not solved independently. Rather, results of these smaller sub-problems are remembered and used for similar or overlapping sub-problems. Dynamic programming is used where we have problems, which can be divided into similar sub-problems, so that their results can be re-used. Mostly, these algorithms are used for optimization. Before solving the in-hand sub-problem, dynamic algorithm will try to examine the results of the previously solved sub-problems. The solutions of sub-problems are combined in order to achieve the best solution.

python , javascript, R ,SQL This graph represents the minimum, maximum, median, first quartile and third quartile in the data set   python   introduction of python  open source, interpreted, high level , general purpose programming language. easiest to learn and nicest to use fewer lines of code compare to other languages Advantages  easy syntax  readability  high level language  its free and open source  cross platform widely supported  its safe huge amount of additional open source library  data stuctures in python - List - list is data structure that holds ordered collection of item. tuple - tuple is imutable ordered sequence of zero or more objects . it allows dublicate values like list set- is a muteble data structure that holds unordered collection of unique items. {} directory - is unordered collection of zero or more key-value pair . its mutable  Data Science - it is branch of computer science where we study how to store , use and analyze data for deriving information from it .

computer network is system in which multiple computer devices are connected to each other to share information and resources  LAN- local area network is computer network that interconnects computer devices within limited area such as school, laboratery . Man- metropolitan area like city . wan- large scale geographical area. protocol- is set of rules to govern data communication  OSI MODEL=  OSI stands for  Open System Interconnection   is a reference model that describes how information from a   software   application in one   computer   moves through a physical medium to the software application in another computer. Internet - is type of world wide computer network  internet is computer network that interconnects hundreds of millions of computer devices throughout the world  WEB-  Web page consist of objects . object can be HTML file,text file, audio file etc.. if webpage consist of HTML text and five images then web page has 6 objects. A web page is given an online address called a U

 Primary key CREATE TABLE CUSTOMERS( ID INT NOT NULL, NAME VARCHAR (20) NOT NULL, AGE INT NOT NULL, ADDRESS CHAR (25) , SALARY DECIMAL (18, 2), PRIMARY KEY (ID) ); CREATE TABLE CUSTOMERS( ID INT NOT NULL, NAME VARCHAR (20) NOT NULL, AGE INT NOT NULL, ADDRESS CHAR (25) , SALARY DECIMAL (18, 2), PRIMARY KEY (ID, NAME) ); ALTER TABLE CUSTOMER ADD PRIMARY KEY (ID); ALTER TABLE CUSTOMERS ADD CONSTRAINT PK_CUSTID PRIMARY KEY ( ID , NAME ); ALTER TABLE CUSTOMERS DROP PRIMARY KEY ; foreign key CUSTOMERS table CREATE TABLE CUSTOMERS ( ID INT NOT NULL , NAME VARCHAR ( 20 ) NOT NULL , AGE INT NOT NULL , ADDRESS CHAR ( 25 ) , SALARY DECIMAL ( 18 , 2 ), PRIMARY KEY ( ID ) ); ORDERS table CREATE TABLE ORDERS ( ID INT NOT NULL , DATE DATETIME , CUSTOMER_ID INT reference