TTU ISQS 3344 Flamm - Exam 1 Review; Exam Questions & ANSWERs 100% Solved and Verified

1. What is the primary purpose of a database? ANSWER: To store and manage data in an organized way for easy retrieval and manipulation. 2. What does DBMS stand for? ANSWER: Database Management System. 3. What is the role of a DBMS? ANSWER: It is software that interacts with end users, applications, and the database itself to capture and analyze data. 4. What is data redundancy? ANSWER: The duplication of data in multiple locations within a database, which can lead to inconsistencies. 5. What is data inconsistency? ANSWER: When different and conflicting versions of the same data appear in different places. 6. What is a primary key? ANSWER: A unique identifier for each record in a database table. It cannot be null. 7. What is a foreign key? ANSWER: An attribute in one table that matches the primary key of another table, used to establish a relationship between the two tables. 8. What is a composite key? ANSWER: A primary key that consists of more than one attribute. 9. What is an entity? ANSWER: A person, place, thing, or event about which data is stored. 10. What is an attribute? ANSWER: A characteristic or property of an entity. 11. What is a relational database? ANSWER: A database that organizes data into tables (relations) which are linked based on common attributes. 12. What is a tuple? ANSWER: Another term for a row or record in a database table. 13. What is a flat file? ANSWER: A simple database stored in a single file, often without structured relationships (like a spreadsheet). 14. What is a query? ANSWER: A request for data or information from a database. 15. What is SQL? ANSWER: Structured Query Language, the standard language for relational database management systems. 16. What is the purpose of the SELECT statement in SQL? ANSWER: To retrieve data from one or more tables. 17. What does the FROM clause in a SQL query specify? ANSWER: The table(s) from which to retrieve the data. 18. How do you select all columns from a table named 'Customers'? ANSWER: `SELECT * FROM Customers;` 19. What is the WHERE clause used for? ANSWER: To filter records and extract only those that fulfill a specified condition. 20. How would you find all customers from the city 'London'? ANSWER: `SELECT * FROM Customers WHERE City = 'London';` 21. What are the logical operators AND and OR used for in a WHERE clause? ANSWER: To combine multiple conditions. 22. What is the ORDER BY clause used for? ANSWER: To sort the result-set in ascending or descending order. 23. How do you sort a query result in descending order? ANSWER: By using the DESC keyword, e.g., `ORDER BY ColumnName DESC`. 24. What is a JOIN in SQL? ANSWER: A clause used to combine rows from two or more tables, based on a related column between them. 25. What is an INNER JOIN? ANSWER: A join that returns records that have matching values in both tables. 26. What is a LEFT JOIN? ANSWER: A join that returns all records from the left table, and the matched records from the right table. The result is NULL from the right side if there is no match. 27. What is a data type? ANSWER: An attribute that specifies the type of data that an object can hold (e.g., integer, character, date). 28. What is the difference between CHAR and VARCHAR data types? ANSWER: CHAR is fixed-length, while VARCHAR is variable-length. 29. What is an ERD? ANSWER: Entity-Relationship Diagram; a graphical representation of entities and their relationships. 30. What is a crow's foot notation? ANSWER: A set of symbols used in ERDs to represent the cardinality of relationships (e.g., one-to-many, many-to-many). 31. What does a one-to-many (1:N) relationship mean? ANSWER: One instance of an entity (parent) can be associated with many instances of another entity (child). 32. What does a many-to-many (M:N) relationship require in a relational database? ANSWER: A bridging or composite entity to break it into two one-to-many relationships. 33. What is normalization? ANSWER: The process of organizing data in a database to reduce redundancy and improve data integrity. 34. What is the goal of First Normal Form (1NF)? ANSWER: To eliminate repeating groups and ensure atomicity (each cell contains a single value). 35. What is the goal of Second Normal Form (2NF)? ANSWER: It must be in 1NF and all non-key attributes must be fully functionally dependent on the primary key (no partial dependency). 36. What is the goal of Third Normal Form (3NF)? ANSWER: It must be in 2NF and have no transitive dependencies (no non-key attribute depends on another non-key attribute). 37. What is a functional dependency? ANSWER: A relationship where the value of one attribute (or set of attributes) determines the value of another. 38. What is a partial functional dependency? ANSWER: When a non-key attribute is dependent on only part of a composite primary key. 39. What is a transitive dependency? ANSWER: When a non-key attribute depends on another non-key attribute. 40. What is an anomaly? ANSWER: An inconsistency or error that arises in a database due to redundancy or poor design. 41. What are the three types of anomalies? ANSWER: Insertion, Deletion, and Modification (Update) anomalies. 42. What is an insertion anomaly? ANSWER: The inability to add data to the database due to the absence of other data. 43. What is a deletion anomaly? ANSWER: The unintended loss of data due to the deletion of other data. 44. What is an update anomaly? ANSWER: Data inconsistency resulting from data redundancy and partial update. 45. What is a surrogate key? ANSWER: A system-generated, unique primary key (like an auto-incrementing ID) with no business meaning. 46. What is the difference between a candidate key and a primary key? ANSWER: A candidate key is any attribute that could be chosen as a primary key. The primary key is the specific candidate key that is chosen to uniquely identify records. 47. What is a superkey? ANSWER: Any set of attributes that uniquely identifies a record. A candidate key is a minimal superkey. 48. What is the purpose of the DISTINCT keyword in SQL? ANSWER: To return only distinct (different) values. 49. How does the LIKE operator work? ANSWER: It is used in a WHERE clause to search for a specified pattern in a column. It often uses wildcards like % and _. 50. What does the % wildcard represent in a LIKE pattern? ANSWER: Any sequence of zero or more characters. 51. What does the _ wildcard represent in a LIKE pattern? ANSWER: A single character. 52. What is the BETWEEN operator used for? ANSWER: To select values within a given range (inclusive). 53. What is the IN operator used for? ANSWER: To specify multiple possible values for a column. 54. What is an aggregate function? ANSWER: A function that performs a calculation on a set of values and returns a single value.