J2-6_dbms_week1_module1

Week1 Module1 1. What is a database? What is DBMS? Ans: -- The Collection of data and operations to perform on that data is called database Collections of programs that manages the database structure and control accessing data called DBMS 2. Why would you choose a database system instead of simply storing the data in Operating system files? Ans:-– Possible to share data among multiple applications or users – Makes data management more efficient and effective – Promotes integration view of organizations operations. – Easy retrieval of data for queries – Data inconsistency greatly reduced( removing same data occurring more than in database) In file system there may be chance to multiple format files, problems in accessing data, data isolation, hard to manipulate data. 3. What is the difference between Logical Independence and Physical Independence? Ans:-In Logical level, it describes the how the data stored in database, and making relationship among the data. Where as in Physical level, it represents how a file or a record is stored in hard disk. 4. What are the different types of languages supported in database? Ans: -- stored Database can supported languages, SQL -Structured query language. QL - object-oriented Data log (4D QL) – 4D Query Language. Hibernate Query Language (HQL) - A Java-based tool that uses modified SQL QBE – Query By Language 5. What is meant by data modeling? Ans:-- Data modeling is the act of exploring data-oriented structures and identifications of relationships among the data objects. Or Data modeling is the analysis of data objects that are used in a business or other context Relationships, inheritance, compositions and aggregations are all the concepts in data modeling. 6. Who are the different types of users accessing the database and in what way? Ans:-- in Users are differentiated on the basis of interact with database.

Application programmers:-- interact with system through data manipulation language. Sophisticated users:--form the requests for querying in database. Naive users: – invoke one of the permanent application programs that have been written previously E.g.:--people accessing database over the web, bank tellers, clerical staff