Relier Pairs DBMS GAMEVersion en ligne INTRODUCTION TO DBMS par RAHUL JHA 1 DDL(Data Definition Language):Data Definition Language (DDL) statements are used to classify the database structure or schema. It is a type of language that allows the DBA or user to depict and name those entities, attributes, and relationships .Here are the lists of tasks that come under DDL: CREATE ,ALTER ,DROP ,TRUNCATE RENAME 2.DML:A language that offers a set of operations to support the fundamental data manipulation operations on the data held in the database. Data Manipulation Language (DML) statements are used to manage data within schema objects. Here are the lists of tasks that come under DML:INSERT,DELETE,UPDATE,SELECT 3.The Data Control Language (DCL) is used to control privilege in Databases. To perform any operation in the database, such as for creating tables, sequences, or views, we need privileges. Privileges are of two types, GRANT,REVOKE 4.TCL:Transaction Control statements are used to run the changes made by DML statements. It allows statements to be grouped into logical transactions. Ex:COMMIT,ROLLBACk 2 1.Railway Reservation System 2.Library Management System 3.Banking 4.Education Sector 5.Credit card exchanges 6.Social Media Sites 7.Broadcast communications 8.Account 9.Online Shopping 10.Human Resource Management 11.Manufacturing 12.Airline Reservation System 3 4 5 6 Slow access time Presence of redundant data Inconsistent Data Data Integrity Problems Difficulty in recovery of corrupt data Lack of Atomicity Problem in Concurrent Access – 7 Define Data Base Management System. 8 1. Reducing Data Redundancy: The file based data management systems contained multiple files that were stored in many different locations in a system or even across multiple systems. Because of this, there were sometimes multiple copies of the same file which lead to data redundancy. 2.Sharing of Data In a database, the users of the database can share the data among themselves. There are various levels of authorisation to access the data, and consequently the data can only be shared based on the correct authorisation protocols being followed. Many remote users can also access the database simultaneously and share the data between themselves. 3.Data Integrity Data integrity means that the data is accurate and consistent in the database. Data Integrity is very important as there are multiple databases in a DBMS. All of these databases contain data that is visible to multiple users. . 4.Data Security Data Security is vital concept in a database. Only authorised users should be allowed to access the database and their identity should be authenticated using a username and password. Unauthorised users should not be allowed to access the database under any circumstances as it violates the integrity constraints. 5.Privacy The privacy rule in a database means only the authorized users can access a database according to its privacy constraints. There are levels of database access and a user can only view the data he is allowed to. 6.Backup and Recovery Database Management System automatically takes care of backup and recovery. The users don't need to backup data periodically because this is taken care of by the DBMS. Moreover, it also restores the database after a crash or system failure to its previous condition. 9 1. Software installation and Maintenance 2. Data Extraction, Transformation, and Loading 3. Specialised Data Handling 5. Security 6. Authentication 7. Capacity Planning 8. Performance Monitoring 9. Database Tuning 10. Troubleshooting 10 1) DBMS applications store data as file. while RDBMS applications store data in a tabular form. 2) In DBMS, data is generally stored in either a hierarchical form or a navigational form. while In RDBMS, the tables have an identifier called primary key and the data values are stored in the form of tables. 3) Normalization is not present in DBMS. While Normalization is also present in RDBMS. 4) DBMS does not apply any security with regards to data manipulation. While RDBMS defines the integrity constraint for the purpose of ACID (Atomocity, Consistency, Isolation and Durability) property. 5) DBMS uses file system to store data, so there will be no relation between the tables. While in RDBMS, data values are stored in the form of tables, so a relationship between these data values will be stored in the form of a table as well. 6) DBMS has to provide some uniform methods to access the stored information. While in RDBMS system supports a tabular structure of the data and a relationship between them to access the stored information. 7) DBMS does not support distributed database. While in RDBMS supports distributed database. List Advantages of database management system. Design an ER diagram for hospital Management system. Differentiate between DBMS and RDBMS. Mention the different language present in DBMS. List the different roles of DBA in database ,management system. Database Management System (DBMS) is a software for storing and retrieving users' data while considering appropriate security measures. It consists of a group of programs which manipulate the database. The DBMS accepts the request for data from an application and instructs the operating system to provide the specific data. In large systems, a DBMS helps users and other third-party software to store and retrieve data. State the applications of DBMS. Design an ER diagram for Library database management system. Design an ER diagram for hotel management system. State disadvantages of file processing system.
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