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Database Engineering: File Systems, DBMS, and Data Independence, Assignments of Database Management Systems (DBMS)

Assignment of Database Management System For Semester

Typology: Assignments

2019/2020

Available from 10/05/2022

PriyankaSubudhi
PriyankaSubudhi 🇮🇳

3 documents

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Database Engineering Asignment_No1
Q1 : List three significant differences between a file-processing system and
a DBMS.
Q2: Explain the difference between physical and logical data
independence.
Q3: Construct an E-R diagram for a car-insurance company whose
customers own one or more cars each. Each car has associated with it
zero to any number of recorded accidents.
Q4: Construct appropriate tables for each of the E-R diagrams
Q5: Explain the distinctions among the terms primary key, candidate key,
and superkey.
Q6: employee (person-name, street, city)
works (person-name, company-name, salary)
company (company-name, city)
manages (person-name, manager-name)
Find the names of all employees who work for First Bank Corporation.
Q1-3CO1
Q4-5CO2
Q6CO3
pf3

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Database Engineering Asignment_No

Q1 : List three significant differences between a file-processing system and a DBMS. Q2: Explain the difference between physical and logical data independence. Q3: Construct an E-R diagram for a car-insurance company whose customers own one or more cars each. Each car has associated with it zero to any number of recorded accidents. Q4: Construct appropriate tables for each of the E-R diagrams Q5: Explain the distinctions among the terms primary key, candidate key, and superkey. Q6: employee ( person-name , street , city ) works ( person-name , company-name , salary ) company ( company-name , city ) manages ( person-name , manager-name ) Find the names of all employees who work for First Bank Corporation. Q1-3CO Q4-5CO Q6CO

ANSWERS Q1 Ans  A DBMS reduces the amount of data duplication by ensuring that a physical piece of data is available to all programs authorized to have access to it, where as data written by one program in a file-processing system may not be readable by another program.  A DBMS is designed to allow flexible access to data (i.e., queries), whereas a file-processing system is designed to allow predetermined access to data (i.e., compiled programs).  A DBMS is designed to coordinate multiple users accessing the same data at the same time. A file-processing system is usually designed to allow one or more programs to access different data files at the same time. In a file-processing system, a file can be accessed by two programs concurrently only if both programs have read-only access to the file. Q2 Ans  Physical data independence is the ability to modify the physical scheme without making it necessary to conceptual or external schema.. Such modifications include changing from unblocked to blocked record storage, or from sequential to random access files.  Logical data independence is the ability to modify the conceptual scheme without making it necessary to change external schemas. Such a modification might be adding a field to a record; an application program’s view hides this change from the program. Q3 Ans Q4. person (driver-id, name, address) car (license, year, model)