The Tech Storror

Information Systems An information system is a system consisting of people and machines, which process data and makes it useful for users. That is, an information system is an integrated system of human resources, hardware, software, communication network and data resources, which collect, store, present, modernize and exchange and process information from one organization to another organization. The use of computers has made data processing much easier, error-free and faster, and the distribution of information between different users or organizations has become much easier. Below are some more definitions of an information system: An information system is a combination of human resources, hardware, software, network systems and data resources that collect, transforms and process the information an organization needs. Technically, an information system is a set of interrelated components that collect, (or retrieve), process, store and distribute information to support organizational ...

Data Transmission System Asynchronous Transmission: A data transmission system in which characters are transmitted from sender to receiver is called asynchronous transmission. In this method the sender does not require any primary storage medium for data transmission. Main features of asynchronous data transmission: (i) The sender does not require any primary storage device for data transmission. (ii) In this method of data transmission the sender can transmit the data at any time and the receiver can also transmit it. (iii) In this method of data transmission, the time between the transmission of one character and the transmission of another character may vary rather than be equal. (iv) Each character has a start bit at the beginning and end transmission is also called start/stop transmission. Advantages, Disadvantages and Uses of Asynchronous Data Transmission Advantages of asynchronous data transmission: (i) At any time the sender can send data and the receiver can receive it. (ii) ...

Differences between database indexing and sorting Indexing (i) It takes relatively less time to sort random data. (ii) After indexing the data file in this method, new records are automatically added to the correct location. (iii) Sorting of data file by indexing method keeps serialization of records of file in main table. (iv) When a data file is indexed, a new index file is created and the original table file remains unchanged. (v) Sorting by indexing requires additional space in memory as additional index files are created. (vi) Alphabetically, Numerically, Indexing can be done. Sorting (i) Sorting random data takes more time than indexing.   (ii) After sorting the data file in this method, if new records are added, the file has to be sorted again. (iii) When the data file is sorted by the sorting method, the serialization of the records in the original table file is not correct. (iv) When the data file is sorted, the original table file is stored in memory in a sorted state. (v...

Question-1. What is data type? Answer: In our daily life we ​​have to work with a lot of data. That is why the use of database for personal and institutional needs is increasing day by day. And the database means a collection of many different types of data. Different types of data are divided into categories according to application or use. These different types of data are called data types. When creating a database in Microsoft Access, it is necessary to determine what type of data will be stored in which field. Database programs perform different operations based on the type of data. Any data entry cannot be done in any field. For example - text for data like letters or letters, numbers for data like numbers or numbers etc. Question-2. What are field properties? Or, what are field properties? Answer: Database has some properties for each field of data table. Field properties are displayed depending on the data type. These data properties determine the shape of the field, how the da...

Various components of the database window  A database is in the form of a container or window, in which similar objects in the database are grouped together. The database window consists of several tabs. Database tables and other objects are stored under different tabs, the object to be created is selected from the database window. Below is a brief introduction to the various components of the database window. Tables: The tables are stored under this tab. From here a table can be changed, modified, or a new database created. Queries: From this tab you can get the list of all the queries in the current database. From here one can manage a query, change the query, modify it or create a new query. Forms: All reports and forms of the current database can be found from this tab. From here a report can be modified or a new report can be created. Report: Report is to display or print the information in the format as desired by the users. Page: Database Access page can be created to work w...

  Data Encryption & Decryption  Data Encryption: Data encryption is to keep data safe from the use of unauthorized persons/organizations. Encrypted data usually prevents unauthorized persons/institutions from accessing the data. The source or sender of the data encrypts the data using specific codes. When the data reaches the destination or recipient, the data has to be decrypted before use. In this case, the sender has to inform the Encrypt rule or the Decrypt rule to the recipient. The original message is changed by decrypting the encrypted data using the same method or algorithm. Different methods of data encryption: There are various types of data encryption rules in use, viz (i) Caesar Code and (ii) Data encryption standards. The Caesar code has been used to encrypt data since the time of Roman Emperor Julius Caesar. The Data Encryption Standard-DES invented by the American National Bureau of Standard NBS is the most widely used encryption method. The method of encryp...

 Basic Concept on Data Security & Authentication Entity Level Security The security system is greatly strengthened by database authorization. Even then, security breaches do occur. Various unauthorized persons breach security through database misuse and accidents. But this is not desirable at all in case of database. Therefore, a security method called encryption is used in the database management system to further strengthen the security system. Data Recovery Database data is lost when the computer system fails or crashes due to any reason. The process by which this lost data can be recovered is called data recovery. Failures are of various types, namely-  (i) Transaction Failure (ii) Logical Error (iii) System Error  (iv) System Crash (v) Disk Failure Authorization Authorization is a process by which database security can be controlled. A database user can have different types of authorizations. This is dependent on database security. When the query processor transl...

Fundamental Operation of SQL SQL in data definition Data is defined or defined using SQL through the CREATE statement. An example is given below CREATE TABLE Employee() Emp_No NUMBER (5) NOT NULL Name CHAR (20) Skill CHAR (20) pay_rate NUMBER (10, 2); Explanation of the statement: (i) A table named Employee can be created through this SQL. The table will have four fields named Emp_No, Name, Skill and Pay_rate. (ii) Emp_No field will be NUMBER type data and this field will never be empty as it is declared as NOT NULL. (iii) Name field will be Character tight data and its length will be 20. (iv) The Skill field will be Character tight data and its length will be 20. (v) Pay_rate field will be NUMBER data type and its length will be 10 and 2 digits after decimal. Now let's say we want to add a new field to this table. Then type the following command: ALTER TABLE Employee ADD Phone_No NUMBER (10); Now type the following command to delete the Employee table. DROP TABLE Employee. SQL in ...

Use of Retrieval Update Function from Relational Data Retrieving function description from relational data-- SELECT statement is used for SQL language retrieval. It can also be used to select data from multiple relations. SELECT statement syntax-- SELECT [distinct] <target-list> form <relation__ list> [where <predicate>] Distinct: Specifies that all attributes will be displayed by default. Distinct clause should be used to avoid displaying any duplicate records in the query. Target-list: List all the attributes to be displayed from a table. Multiple attribute names are separated by commas. Relation list: All the tables that will be evaluated i.e. all the tables from which the data will be selected must be mentioned in the <Relation list> part with the form clause. Predicate : Predicate is to be specified with where clause. Here data can be relative from multiple tables by defining a relation attribute as Predicate.

Relationship & Entity Set   Relation: To work with large amount of data, different types of data tables have to be created. Various types of data can be presented and used as desired by establishing relationships between data in one data table and another data table. The relationship between data in one data table and data in one or more data tables is called a relation. All the data tables in which the relation is to be established must have at least one common field. Relationships are established based on this common field. Data relationships cannot be created at will. For this, some conditions have to be met, such as-  (i) A relational data table should have a common field, which field name, data type, field size format, etc. should be exactly the same. (ii) A field in a relational data table is identified as a primary key. Relationship Benefits: Establishing relationships between multiple data tables provides many benefits. Some of the notable ones are-- (i) It is easy...

Data Manipulation Language A data manipulation language is a language that allows the user to read, add, and delete previously stored data from a database. Functions in the Data Manipulation Language or DML can be used directly by application programs in the data management system. E.g.- Employee Name entity set or file has attributes Employee Name, Employee ID Number, Last Name, Address etc. Now if you need to see the name and surname of the employees from among them, then it is possible to see it with data manipulation language. There are two types of data manipulation languages ​​namely--  (i) Procedural (ii) Non-Procedural. Description of Data Manipulation Language Statements: (i) Select statement SQL language Select statement is used for data retrieval. It can also be used to select data from multiple relations. Syntax of SELECT statement- SELECT [district]<target list> from <relation list> [ where <predicate >] (ii) UPDATE statement UPDATE statement is used ...

Client Server & Distributed Database Client Server: The current era is the era of information technology. And in this era everything is normal to be covered by computer network. Computer networks can be of different types. PC based network based on client server software is called client server. Client server network is the most accepted and trusted network. Client-server databases are used in cases where multiple users need to work at the same time or at different times through the same database connection. In this system there is a central computer, called the server computer and the computer/terminal connected to it is called the client. The main database is permanently stored on the server and remote users can access the server computer's database by connecting to the client, server computer. The client can share all the resources of the server. Again, the server computer can also assist the client computer if necessary. The operation of client server database can be divid...

Attribute, Entity, Data value Attribute Fields or items or elements used to express the properties of an entity are called attributes. For example, a teacher's name, address, phone number, department, etc. is an attribute. Attributes can be of two types. (i) Simple Attributes (eg Name, Address etc.) (ii) Composite Attributes (eg – First Name, Last Name, Road No., House No., Area etc.).  Entity Entity is the main unit required for standard classification of real or non-real objects. The entity may have real presence or it may be based only on concept. Examples of data entities are building, room, chair, business contract, syllabus, machine, employee, country, nation, student, teacher etc. Of course NT will have some properties. Eg - student is an entity whose attributes are student name, roll no, age, class etc. An entity type or entity set for an organization is a set of similar 'objects' containing data related to that organization. So the entities associated with the subj...

Types of Database Management System Database management systems can be divided into various categories, namely, client server databases, distributed databases, hypermedia and web databases. They are described below: Client Server Database: In the client server network system, the server and the work station are both processed, that is, both the server and the workstation can work. As a result, certain tasks can be outsourced to servers and workstations as needed. Workstations can use the server's resources and the server can assist the workstation in processing tasks. Client server database is established based on this concept. The client sends a request to the server to obtain a service; The server provides data or services according to the client's request and other rules. The operation of client server database can be divided into two, namely— (1) Front-end  (ii) Back End The front end of the database system consists of several tools such as forms, reports, graphical user i...

System Development Method: The strategy adopted by a development group to create an organization's information system using various tools and techniques is called the information system development method. Currently, there are various development methods used to create information systems, such as waterfall model information, spiral model, prototype model, etc. Among them, the waterfall model is quite old; But nowadays it is used in many cases. Information system implementation in the waterfall model is a structured process. This process consists of several interrelated steps. The different stages of the waterfall model are also called system development cycles. System Development Life Cycle (SDLC):  System development involves correcting the existing system by removing its defects, disadvantages, etc., formulating its well-planned outline through judicious analysis and research to establish a completely new system. The system development cycle is a cyclical process. In this cycli...

Software Piracy  Software piracy is a major problem for software manufacturing companies. Software piracy refers to the act of copying software without the permission of the manufacturer, distributing it under one's own name or continuing it as one's own through any modification. That is, software piracy is making illegal copies of software for sale or use without paying royalties to software producers. The process of developing and testing a new software before releasing it is very expensive and the theft of software due to piracy causes huge financial loss to the organization. As a result of software piracy, a software can be used without a license, on the one hand it reduces the intellectual value of the program, on the other hand it causes financial loss. Many countries around the world have copyright laws to protect the copyright of programs. Copy right law in the United Kingdom (UK) makes it illegal to make additional copies of software for use or sale without permission....

Logic bombs Logic bombs are instructions written in computer code, which Can be hidden in the software and activated at a specific date and time. Once activated, logic bombs begin to take control of the computer and damage or even delete data files. Criminals intimidate businesses into doing this and demand money from them.

Flip-flop   Flip-flop is a type of memory element. Flip-flops are used as the internal memory of computers. Binary information with digital signals is stored with the help of electronic circuits. The circuit used for this purpose is called flip-flop. It is abbreviated as FF. FF circuit has two inputs and two outputs. Applying a voltage of level one binary 1 and the other binary 0 to the two inputs produces digital outputs labeled binary 1 and binary 0 to the output two. Now if the input level is reversed, i.e. 1 where it was before and 0 where it was 1, then the output signal is also reversed. So the output of FF can be set to either 1 or 0 state as desired by the input. Latch : FF circuit is also known as latch. The word latch means door hook. When the hook is attached, the door is closed and the door can be opened by opening the hook. Likewise, keeping the latch circuit in the set state (Q = 1, and Q = 0) preserves logic (1). This is why the FF circuit is known as a latch. B...

Difference between manual information system and computer based information system Computer Based Information System: (i) Computer based information system consists of human resource hardware, software, communication network and data resources. (ii) These systems use hardware, software, communication networks and data resources. (iii) The process of data processing is much easier, the effort is much less but the result is much more than that. (iv) It is also less time consuming and error prone. (v) collects, transforms and processes the information of an organization with the help of such information system and provides it as required by the organization. (vi) Examples of Computer Based Information Systems: Office Automation System, Management Information System, Transaction Processing System, Management Support System, Bank Management System etc. Manual Information System (i) Manual information system without computer or any other electronic equipment, making, using and exchanging inf...

Role of Computer in Information Systems The role of computer in information system is very important. Below is the role of computer in information system. Data collection: Information systems collect, store and provide data. These tasks are done with the help of computer. With the help of computer network, scattered data is collected, that is, the role of computer is very important in data collection. Data Organize: The data collected in the information system is organized with the help of computers. The information is then used as needed. Various computer programs solve this formatting task. As a result, the scattered data turns into essential information. Support Network Establishment: Network establishment is impossible without a computer. Information networks are developed with the help of computers. As a result, users can exchange different information with each other. Data Storage: Data is stored in the information system. A complete information system cannot be developed without...