PROGRAMMING APPLICATIONS AND FRAMEWORKS

DATA PERSISTENCE     DATA, FILES, DATABASES, AND DBMSS Data Data are row facts  Can be processed (by application components) and converted to meaningful information Data persistence  Working data is contained in computer memory  Memory is volatile Data should be saved into non-volatile storages for persistence Data persistence techniques  Data can be stored in  Files  Databases Files VS Databases Data arrangement  Un-structured  Semi-structured  Structured Database Databases are created and managed in database servers  SQL is used to process databases  DDL –CRUD databases  DML –CRUD data in databases Database type  Hierarchical databases  Network databases  Relational databases  Non-relational databases (NoSQL)  Object-oriented databases  Graph databases  Document databases DBMSs DBMSs are used to ...

RESTful Web services REST   • Representational State Transfer (REST) is an architectural style for the service of web • The REST is used as a basis for HTTP 1.1 development    • Thus the WWW including servers, proxies, etc... • REST is    • Resource-based   • Focuses on Representations (of data/information/resources)     • Derived using Six Constraints   CONSTRAINTS 1) Client-server 2) Layered System   3) Stateless   4) Cacheable   5) Code-On -Demand (Optional)     6) Uniform Interface   ELEMENTS OF REST STYLE        

Web Service World Wide Web Consortium describes web service as a system of software allowing different machines to interact with each other through network. Web services achieve this task with the help of XML, SOAP, WSDL and UDDI open standards. XML :   The full form of XML is ‘Extensible Markup Language’ which is used to share data on the web and in universal format. SOAP :  Standing for ‘Simple Object Access Protocol’ which is an application communication protocol that sends and receives messages through XML format. It is one of the best ways to communicate between applications over HTTP which is supported by all browsers and servers. WSDL :  Written in XML, WSDL stands for Web Services Description Language and is used to describe web service. WSDL comprises three parts such as Definitions (usually expressed in XML including both data type definitions), Operations and Service bindings. Operations denote actions for the messages supported by a We...

1. Explain the term “distributed systems”, contrasting it from “distributed computing” ? Distributed system : a collection of independent computers that are connected with an interconnection network. Distributed computing : a method of computer processing in which different parts of a computer program are run on two or more computers that are communicating with each other over a network. 2. Compare and contrast the standalone systems with distributed systems, providing examples for advantageous use of both ?  A standalone device is any mechanism or system that can perform its function without the need of another device, computer, or connection. A perfect example of a standalone device is a copy or fax machine, as shown in the picture .   Standalone system  All the components are executed within a single device  Do not need a network Usually one or tightly coupled set of technologies are used to develop (JAVA, .NET) Distributed system ...