IT and Project Managment related Questions

Session 1 Database Systems Session 1 Objectives 1. The difference between data and information 2. What a database is, the various types of databases, and why they are valuable assets for decision making 3. The importance of database design 4. How modern databases ev olved from file systems 5. About flaws in file system data management 6. The main components of the database system 7. The main functions of a database management system (DBMS) Review Questions 1. Discuss each of the following terms: a. data b. field c. recor d d. file 2. What is data redundancy, and which characteristics of the file system can lead to it? 3. What is data independence, and why is it lacking in file systems ? 4. What is a DBMS, and what are its functions? 5. What is structual independence, an d why is it important? 6. Explain the difference between data and information . 7. What is the role of a DBMS, and what are its advantages? What are its disadvantages? 8. List and describe the different types of databases. 9. What are the main component s of a database system? 10. What are metadata? 11. Explain why database design is important. 12. What are the potential costs of implementing a database system? 13. Use examples to compare and contrast unstructured and structured data. Which type is more preva lent in a typical business environment? 14. What are some basic database functions that a spreadsheet cannot perform. 15. What common problems do a collection of spreadsheets created by end users share with the typical file system? 16. Explain the significance of the loss of direct, hands -on access to business data that users experienced with the advent of computerized data repositories. (These questions are intended ONLY to be a self -test of your comprehension of this session's material; answers to these question s do not need to be turned in. ). These questions are just for your guidance. Lecture Notes OVERVIEW This is an introductory session which covers the following core topics:  Difference between data and information  Database and types of databases  Database design and its importance  Evolution of modern database from file systems  Components of database system  Functions of database management systems (DBMS) Database is an essential feature and plays an important role in our every day life, let it be banking transactions, making purchases online or grocery shopping. When we visit a consumer website like Amazon to order books or electronics, we are accessing a database. When we visit an interactive customer service website, we are able to access informa tion about our own records of services provide d. For example, we can go to ups. com or fedex. com to locate our packages’ whereabouts. Through online banking, we can easily check our deposits, withdrawals, bill payments, and other transactions that are store d in the bank’s database. Many more examples of using database can be found in airline reservations, medical records and billing, employment records, school records, bibliographic databases, and so on. Database are crucial for ensuring ease of operating b usinesses especially to make the business operate effectively and efficiently provided the databases are well designed. Difference between data and information This session discusses some of the salient features of database design concepts. First of all, it is important to understand the core differences bet ween data and information which leads us to the concept of storing data by introducing database. As Matthew Johnson point ed out, data are basically raw fact, but without being analyzed and processed to information, it means nothing and has little value.

Business information and knowledge can directly assist decision making. For example, for a retailer, the daily, weekly, or monthly sales are data. Based on the raw data, we can identify more useful information such as the best selling items or the most productive salespersons. Here is a more detailed example of the differences between data and information. Database and types of databases Data must be stored and organized properly so that they can be processed easily and accurately to generate information. Databases are created to fulfill the task – the proper generation, storage, and retrieval of data. Even though they all share some common characteristics and benefits , there are various types of databases (single user, multi -user, enterprise database, centralized database, distributed database and so on) based on number of users, location, or data usage. Keep in mind that as technology evolves there are many different methods to classify databases . Database design and its importance As databases play critical role in organizational data management and decision making, it is important to design databases right . A poorly designed database will not achieve its goal and even worse, can lead to bad decision making, and ulti mately lead to the failure of an organization. Evolution of modern database from file systems Moving further into the session 1, it is critical to understand the evolution of the current database systems which had their origin from the manual file systems ( MFS ) implemented with punch cards, and then moved to computerized file system implemented with paper tape, magnetic tape, magnetic disk, and newer devices. At the beginning, sequential file processing was used as it was the way to access information stored in devices such as a tape. Once direct access devices such as disks were developed, direct file processing replaced sequential file processing. The file system based data storage had many shortfalls and could lead to inaccurate, outdated, or inconsistent information. That led to some innovations in database systems. Compared with the file system or small isol ated databases, which generally creates the “islands of information”, the modern, integrated database approach to implementing data storage has many advantages. For example, an integrated database facilitates sharing of data so that many users can access t he same piece of information. It can reduce redundancy and minimizes data inconsistency as multiple copies of the same data are not stored unless necessary. It improves data security as an enterprise database allows security restrictions to be defined and enforced on several levels. An integrated database can also improve data integrity, better balance conflicting requirements, develop new applications faster, and provide better data accessibility and backup and recovery procedures. Components of database system and DBMS core f unctions The session finally concludes with explaining some of the core functions of DBMS and the challenges of managing the database systems. A database management system consists of several main components – software, hardware, data, procedures, and people. A DBMS performs several important functions to ensure the integrity and consistency of the data it manages. Some of the core functions include data dictionary management, data storage management, data transformation and presentation, security management, multi user access control, bac kup and recovery management, data integrity management, database access languages and application programming interfaces , and database communication interfaces. It is essential to note that though database s have distinct advantages over file systems , they do come with some disadvantages as well. For example, databases would incur significant cost and management complexity .