Dbms

motility 1: What is infobase? resolve: A selective informationbase is a logically coherent collection of data with most inherent meaning, re donationing some aspect of real world and which is designed, built and populated with data for a specific purpose. header 2: What is DBMS? termination: ? Redundancy is controlled. ? Unauthorised access is restricted. ? Providing multiple user interfaces. ? Enforcing fairish play constraints. ? Providing backup and rec every limity. psyche 4: What is a database governing body? practise: The database and DBMS softw are together is called as infobase system. QUESTION 5: Disadvantage in File Processing remains? effect: ? Data redundancy & inconsistency. ? Difficult in accessing data. ? Data isolation. ? Data fairness. ? Concurrent access is not possible. ? Security Problems. . QUESTION 6: Describe the three directs of data abstraction? response: The are three levels of abstraction: ? Physical level: The concluding lev el of abstraction describes how data are stored. ? Logical level: The near higher level of abstraction, describes what data are stored in database and what family relationship among those data. ? View level: The highest level of abstraction describes merely fibre of entire database. QUESTION 7: Define the integrity rules ANSWER: There are two justice rules. ? Entity Integrity: States that ?

Primary let on cannot have unsatisfying place? ? Referential Integrity: States that ? inappropriate Key can be either a NULL value or should be Primary Key value of other relation. QUESTION 8: What is extension and in tension? ANSWER: Extension -It is the numbe! r of tuples present in a card at any instance. This is age dependent. Intension - It is a unending value that gives the name, structure of parry and the constraints laid on it. QUESTION 9: What is System R? What are its two major subsystems? ANSWER: System R was designed and developed over a period of 1974-79 at IBM San Jose Research Center . It is a prototype and its purpose was to controvert that it is possible to build a...If you demand to get a affluent essay, order it on our website: BestEssayCheap.com

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