Tutorial 1 1. Compare and contrast between the main characteristics of the database and file-based approach. PDF

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1. Compare and contrast between the main characteristics of the database and file-based approach.

2. Describe four government sectors that would be expected to make use of database systems...

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Database Systems 2020-2021

Tutorial 1 Tutorial Questions 1. Compare and contrast between the main characteristics of the database and file-based approach. Databases have a system catalogue which is the data about the data whereas the catalogue for a file-based approach is separate from the programs that access it and each program defines and manages its own data. Database is a shared collection of logically related data made for the needs of a business, but a file-based system is a collection of application programs that carry out services for the end user. File based systems have information that has been processed for one set function databases data that is logically related through entities, attributes, and relationships based upon the organisations information 2. Describe four government sectors that would be expected to make use of database systems Tax- store records of peoples income tax, corporation tax etc. Drivers-strore information about all the people who have a valid license in the UK Records-Information about a person e.g. address, name, age, criminal cinvictions etc. Public Health-All the information of the illnesses and injuries people have been treated for. 3. What is meant by the terms: a. Database Shared collection of logically related data which meets the info needs of a company b. Database Management System Software system that allows users to define, maintain, and control access to the database c. Database Application Program A program that interacts with a DB by issuing a SQL statement to the DBMS d. Data Independence Separating file structures from the programs e. Security Protecting the database from unauthorised users f. Integrity Accuracy of data g. Views A subset of the database 4. Describe the role of database management systems (DBMS) in the database approach. Discuss why knowledge of DBMS is important for database administrators. DBMS organises a collection of data and ensures the integrity of the data by using controls and provide maintenance to the data files. It also permits specification of data types and constraints. DBMS knowledge is important to a

Database Systems 2020-2021

database admin because it gives them a way to efficiently handle large amounts of data and different types. 5. Describe the five components of the DBMS environment. Procedure-instructions for the use and design of DBMS People-The people who create and run the databases Hardware-Could be a singular PC or a whole network Software-OS, DBMS, application programs etc Data-used by the company sored in the DBMS 6. What are the advantages of database management systems? Are there any potential disadvantages? Advantages- Better access to better managed data, provides better data security, efficient way to store large quantities and different varieties of data Disadvantages- Require skilled staff to be able to run and maintain a DBMS, Higher costs for organisation with the need of expensive hardware and software. 7. Discuss the roles of the following personnel in the database environment: a. Data Administrator Use software to store, maintain and organise data b. Database Administrator Ensure the software database is well maintained manages a company’s data c. Logical Database Designer Identify data, relationships and limitations of data d. Physical Database Designer Decides how the records of data will be stored e. Application Developer Creates and tests applications f. End-Users The person that will use the product or service 8. Discuss the three generations of DBMSs. The first gen was the hierarchical approach which were based on smaller components being joined together to create a larger component which then creates final product. The second generation of DBMS is the relational model where data was represented in tables which consisted of a combination of rows and columns where rows are records and columns are attributes. Finally, the third generation was an iteration on previous ones and created two new systems one being the object-relational DBMS and the other being the object-oriented DBMS. 9. Why are views an important aspect of database management systems? Views allow for better security because each user is given specific permissions to access a DB through a small set of views that only the user is allowed to see and it restricts the access to others from viewing it.

Database Systems 2020-2021

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