EF-Code

1. Q-What is database?And How many Types of Databases.A database is a structured collection of data thatis stored and managed in a computersystem. It can be accessed, modified, and queried by authorized users or applications. Thedata in a database is organized in a specific way that makes it easier to retrieve, manageand update the information stored within it.There are several types of databases, including:Relational databases-which store data in tables with predefined relationships between them.NoSQL databases-which are non-relational databases that store data in different ways, such asdocument-oriented or key-value pairs.Object-oriented databases-which store data in the form of objects.Hierarchical databases-which store data in a tree-like structure.Network databases-which store data in a graph-like structure.There are many other types of databases as well, includinggraph databases, time-seriesdatabases, and more.The choice of the type of database depends on the specificrequirements of the application or system that will be using it.ADatabase Management System, orDBMS, is comprised of a wide range of application programsthat enable the efficient access, management, and updating of interconnected and highly durabledata. Similar toother management systems, the primary objective of aDBMSis to create a user-friendly and effective environment for storing and retrieving information from a database. It is well-known that databases are utilized for managing and storing fast quantities of data.
2. What is Relational database??A relational databaseis a type of database that stores data in tables with predefinedrelationships between them. Each table in a relational database represents an entity, and eachrow in the table represents an instance of that entity. The relationships between the tables areestablished through keys that are shared between the tables.The father of the relational database isDr. E.F. Codd, who introduced the concept in a paper titled “ARelational Model of Data for Large Shared Data Banks” published in 1970. Dr. Coddwas a computerscientist at IBM and his work laid the foundation for the development of the modern relational databasemanagement systems that we use today.Who is Dr. Ef Codd??Dr.Edgar F. Codd, also known asEF Codd, was a British computer scientist and mathematician who iswidely regarded as the father of modern relational databases. His work on developing a new data modelfor managingdata in databases laid the foundation for the development ofStructured Query Language(SQL)and modern database management systems. In this blog post, we will take a closer look atEF Coddand his contributions to the field of database management.EF Codd and the Relational Data ModelIn the early 1960s, EF Codd was working at IBM’s San Jose Research Laboratory. At the time,databases were primarily managed using hierarchical or network models, which had limitations interms of flexibility and data retrieval. EF Codd proposed a new data model for managing data indatabases, which he called the “relational data model.” This model was based on mathematical settheory and provided a more flexible way to manage data in databases.The relational data model consisted of the following key components:Tables: Data was stored in tables consisting of rows and columns.Attributes: Columns in a table represented attributes, which described the characteristics of thedata.Primary Keys: Each table had a primary key,which was a unique identifier for each row in the table.Relationships: Tables could be related to each other using keys, which allowed data to be retrievedacross multiple tables.
3. The Importance of EF Codd’s WorkEF Codd’swork on the relational data model had a profound impact on the development of moderndatabase management systems. Here are some key reasons why his work was so important:Improved Data Retrieval:The relational data model made it easier to retrieve data from databases,which was a major improvement over the hierarchical and network models.
4. Increased Flexibility: The relational data model provided greater flexibility in terms of how datawas managed and retrieved, which made it easier to work with databases.Standardization: The relational data model laid the foundation for SQL, which became astandardized language for managing data in databases.Reduced Data Redundancy:The relational data model reduced data redundancy, which meant thatdata was stored in a more efficient manner.Examples of EF Codd’s Work in MS SQLEF Codd’swork on the relational data model is evident in modern database management systems, such asMicrosoft SQL Server. Here are some examples of how his work is applied in MS SQL:Tables:MS SQL uses tables to store data, with each table consisting of rows and columnsAttributes:Columns in MS SQL tables represent attributes, which describe the characteristics of thedata.Primary Keys:MS SQL uses primary keys to uniquely identify each row in a table.Relationships:MS SQL allows tables to be related to each other using keys, which allows data to beretrieved across multiple tables.Rules by EF CoddThe following are the FundamentalRules of Relational Databases:A RDBMS can only use its relational capabilities to manage stored data.Data in the database must be represented in only one way, as values in a table.All atomic data must be accessible through a combination of table name,primary key value, andcolumn name.Null values should be systematically used to represent missing information and are distinct fromempty strings or zeros.The Data Dictionary contains metadata, and authorized users can use the same relational languagetoaccess it as they do for regular data.The system must support a data sublanguage that includes data definition, view definition, datamanipulation, integrity constraints, authorization, and transaction boundaries.Views, or virtual tables in the database, must update along with their base tables.The system should be able to handle base or derived relations as a single operand for datamanipulation.Changes to storage representation or access methods should not impact application programs orterminal activities.Changes to the base tables that preserve information should not impact application programs orterminal activities.Integrity constraints must be definable in the relational data sublanguage and stored in the catalog,not in application programs.
5. The system must support centralized or distributed data manipulation without impactingapplication programs or terminal activities.Low-level languages cannot be used to bypass integrity rules or constraints expressed in higher-level relational languages.
6. Advantages of Relational Databases:Structured: Relational databases are structured and organized in a way that makes it easy to store,retrieve, and update data. This structure ensures that the data is consistent and accurate.Scalability: Relational databases can handle large amounts of data and can be scaled to meet theneeds of growing applications and organizations.Flexibility: They allow for ad hoc querying and reporting, providing greater flexibility in dataanalysis.Security: Relationaldatabases provide built-in security features such as access control, encryption,and backups, ensuring that data is protected from unauthorized access and loss.ACID compliance: Relational databases are ACID-compliant, meaning they guarantee transactionalconsistency, isolation, and durability.Disadvantages of Relational Databases:Cost: Relational databases can be expensive to set up and maintain, especially for large-scaleapplications.Complexity: They can be complex to design and implement, requiring specialized skills andexpertise.Performance: Performance can be a challenge for very large databases or in cases where complexqueries are used.Limited scalability: Although relational databases are scalable, they can be limited in their ability toscalehorizontally across multiple servers.Schema changes: Making changes to the schema of a relational database can be difficult, especiallywhen the database is in use, and requires careful planning and execution.ConclusionEF Codd’swork on the relationaldata model had a profound impact on the development of moderndatabase management systems. His ideas formed the basis ofSQL, which has become a standardlanguage for managing data in databases. By providing a more flexible way to manage and retrievedata,EF Codd’swork has made it possible to store and access large amounts of data moreefficiently than ever before. Today, his work remains an important part of the foundation ofmodern database management.E.F. Coddwas a computer scientist who laid the foundation for the relational databasemanagement system. His work defined the12 fundamental rulesof a relational database thatensured data integrity, consistency, and ease of use. Codd’s contributions to the field of databasemanagement have led to the development of modernRDBMStechnologies that haverevolutionized the way we store, manage and access data