The Tech Storror

 Index Large books have indexes or indexes at the end to facilitate the search for various topics. Through it, it is known that a topic has been discussed on some page of that book. In the case of database also there is system of such index to find various data quickly. Such indexes increase the performance of searching for any information in the database. Simply put, an index is a pointer to data in a table. The created index is stored in a different location from that table. The main purpose of the index is to speed up data retrieval from the database. Indexes can be created or deleted without changing the data. However, queries may take longer if an index is deleted. Keep in mind that indexes occupy physical space and in some cases may be larger than the original data table. Databases need to create indexes to increase query performance. Indexes can be created during table creation or later. The create index statement creates an index for a column in a table. However, it should ...

There was a time when science and technology were not so complex. We used to spend a lot of time entertaining to watch a few channels on our home television. Contact was made by letter, stamps were purchased from the post office, wrapped in a paper envelope, stamped and dropped in the mailbox for destination. Then the telephone set is actually a wired voice communication system. From the office to the court, people would take a telephone connection at home. Then the real mobile phone, but with it only voice calls could be made. That was not long ago, 15 years ago. The technology was very simple. But since 2005, high bandwidth (bandwidth key), affordable internet, computers, later smartphones and other technologies have changed the world. But one thing must be admitted, that is that the Internet is at the root of all our so-called modern technology. Everything is now online due to the vastness and convenience of the internet. We all rely on online now. Starting from television channels,...

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...

Question-1. What is database? Answer: The word Data means data and the word Base means assembly. So a collection of interrelated data that can be stored in a computer is called a database. For example, information of students of an institution, voter list, information of employees of a company, etc. Question-2. What is the field? Answer: Different parts of the record are called fields. Basically column heading is called field. such as  Name, Roll, Class, Age are each separate fields. Question-3. What is the record? Answer: The collection of data of several fields of a Data Table is called Record. Basically, the Record is obtained by combining the data of the rows of the Table. Question-4. What does the word query mean? Answer: Displaying specific data from a database through specific conditions very quickly and easily is called a query. Data can be conveniently selected using expressions, operators, filters, etc. in the query. Queries can be of various types are--- (i) Select Query...

Query Language User can easily retrieve information or data from database with query language. Operations such as entering data, retrieving data, modifying or deleting data in the database are called queries. The language with which queries are made is called query language. Most database management systems use query languages ​​to access the database. It is a high-level language. Using this language, it is possible to easily search and collect data from the database and perform various calculations according to the user's wishes. This language is higher level than any standard programming language. SQL and QUEL query languages ​​are currently used in microcomputers. Name some query languages (i) QUEL (Query Language) (ii) QBE [Query by Example] (iii) SQL (Structured Query Language) (iv) Server SQL Among these four query languages, SQL has gained the most popularity worldwide. According to ANSI standards, SQL has become the standard query language for relational databases. SQL and ...

OBJECT ORIENTED DATABASE MODEL  Object Oriented Database Model: Object-oriented programming is basically divided into two phases: object-oriented analysis and object-oriented design. In the analysis phase, according to the type of problem described in the system, the main problem is divided into several small units or objects, and connections are established based on the results obtained from them. And in the design phase, by reviewing the classes or objects declared in the analysis phase, the classes, member functions and driver programs are designed by determining the class dependency, class hierarchical. Steps of Object Oriented Analysis: (i) Analyzing and understanding the main problem. (ii) Describing user needs. (iii) Dividing the original problem into smaller parts or objects as required. (iv) Determining the properties of objects. (v) Determining the desired results from the objects. (vi) Making connections between objects based on desired and achieved results. Steps of Ob...

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.

Composition of Network Data Model and Relational Data Model --- Network Data Model A network database contains links between records. This is very similar to the NTT relationship model. Difference between network data model and relational data model: Network Data Model: (i) Linking between records in the database. (ii) Complex linkage between organization records is used. (iii) It is very similar to NTT relationship model. (iv) A record can be connected quickly with the help of organization Relational Data Model: (i) Different types of relationships exist in such databases. (ii) Creates relationships between tables. Records are used. (iii) Many tables are related to each other. (iv) Relationships between one table and another can be linked.

Binary Relationship  A data structure diagram that links only two record types is called a binary relationship. This is similar to the binary relationship of the E-R diagram. Binary relationships are basically of 3 types, viz-- (i) One to One (ii) One to Many and (iii) Many to many. If the binary relationship is One to One then the arrow keys will be on either side of the link. But if the relationship is One to Many or Many to One, then either side of the link will have its mark on one side.   General Relationship: Basically, the relationship method that establishes the relationship between more than two records is called general relationship. General relationships are usually shown by boxes and links. For example, consider an E-R diagram made up of three entities, Customer, Account and Branch, which are related to the general relationship CAB.  E-R diagram to show general relationships of network data model Data Structure Diagram following steps should be taken: (i) Enti...

Data Structure Diagram A data structure diagram is a schema that represents the design of a network database. There are two basic components in this diagram. For example, boxes and boxes represent or correspond to record types. Data Structure Diagram is used for the same purpose as Entity Relationship Diagram. That is to say, the data structure diagram specifies the overall logical structure of the database. So, E-R diagram can be translated into Corresponding Data Structure Diagram.

Entity Relationship Diagram It is also possible to show the logical structure or relationships of a database using a block diagram, called an entity relationship diagram. It is much easier to understand the whole thing with the help of block diagram than to describe it in writing. There are some general rules to follow for expressing the database using block diagrams. Apart from that some symbols can be used. The symbols used carry special meanings. Examples of Basic Symbols Used in NTT Relationship Diagrams--- Several symbols can be used to show the logical structure or relationships of a database using block diagrams as well. The symbols used carry special meanings. Some of the common symbols used in the NTT relationship model are--- Rectangle -- Set entity Ellipse- attribute Diamond -- Relationships Straight line -- contains attributes and connectors of NTT sets and NTT sets.

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 ...

Data Dictionary Database data is organized in data dictionary. A data dictionary is nothing but a database. Any database user can learn about the shape, nature, etc. of each data using the data dictionary. Data dictionary function-- (i) Concept of shape nature of database (ii) Organize the database (iii) Describe the database (iv) Examining the database file.

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...

Types of data view labels  There are three types of data view labels, complete with-- (i) External View (ii) Conceptual view (iii) Internal view to describe briefly--- (i) External view  : External view or user view is the topmost position of the database system. An external view is described by an external schema (schema). Entities, Attributes, Relationships etc are all covered. The external label contains the client itself. A customer of any scheme can get the loan related information as per his/her need by going down. But the status of the customer is not possible after knowing the insider of the other. (ii) Conceptual Global View: It is described by the conceptual schema, including all the entities in the label database and the relationships between them. A schema indicates the flow of information from the internal view. For example, the responsibility of the schema rests with the head of the ownership party. Those who can transact with customers can say that customers h...

Elements of Database Environment Building a database system requires a modern database environment. Modern database environments require different components. The following shows the major components of a modern database environment and their interrelationships. (i) Computer Aided Software Engineering Tools -CASE Tools: A type of software tools, which automatically help the system development process. Case tools are used in database design and application programming. (ii) Repository: It is a central knowledge repository, which contains data descriptions, data relationships, forms and report formats and other components of the system. Various components of database management system like other components of information system are stored in this repository. (iii) Database Management System: A database management system is a set of software used to create, modify, store, control and manage databases. Databases and repositories can be created, maintained, and controlled, usually through c...

1. Investigation  In this step of processing, the nature of the problem, the cause of the problem and the possibility of solving the problem are considered. The factors that are considered in this step of information search are:  (i) To know about existing procedures and to inspect if necessary. (ii) System selection through survey work (iii) Possibility of system solution (iv) To judge the feasibility of the system and (v) Preparation of reports. Then data is collected from reports, documents etc. and decisions are made about the objectives, features and other necessary aspects of the proposed method. The feasibility of the system is judged by comparing and analyzing different systems. System Feasibility Report is prepared after data analysis. The report covers the following topics-- (i) Basic description of the proposed system including features, (ii) the economic, technical, institutional and managerial feasibility of the proposed approach and  (iii) Outline of propose...

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...