WGU D427 Practice Questions and Answers correct

WGU D427 Practice Questions and Answers correct What is a datbase? A structured collection of data Which component is responsible for executing instructions from the query processor? Storage engine The BETWEEN operator checks if a value is: Between an inclusive range of two values Which relationship involves a salesperson and products they sell? Binary What does the 'many' in a 1-M relationship imply? No exact numerical limit but more than one MySQL architecture is organized into how many layers? Four In a unary relationship, what kind of relationship is described? A relationship where an entity is related to itself What does modality represent in an ER Diagram? The minimum number of entity occurrences that can be involved in a relationship Which storage media has the fastest access time? Main memory (RAM) Which of the following is NOT a characteristic of a database system? Stores data in an unstructured format Which SQL command is used to delete a table? DROP TABLE MySQL Workbench is designed for: Both database administrators and users What is a primary function of a Database Management System (DBMS)? Managing database security and access What is an associative entity? An entity that is used to represent a many-to-many relationship with attributes The IN operator is used in a WHERE clause to: Check if a value matches any value in a list What does CRUD stand for in the context of database operations? Create, Read, Update, Delete What is an entity in an ER model? A person, place, product, concept, or activity What does a unique attribute signify in ER modeling? An attribute that identifies each entity instance uniquely What is a composite attribute? An attribute that can be divided into smaller parts, each representing a more basic attribute Which of the following best represents a ternary relationship? A relationship involving three different entity types Which operation combines rows from two tables based on related columns? JOIN What characterizes a table cluster? Interleaves rows of two or more tables in the same storage area. Who introduced the relational model? E.F. Codd What is the term for a row in a relational database? Tuple _______________ ensures the consistency and validity of relationships between tables. It dictates that foreign key values in one table must either be null or match primary key values in another table (or the same table in the case of self-referencing relationships) Referential integrity In SQL, which command is used to add a row of new data into a table? INSERT INTO To convert a string to lower case in SQL, which function is used? LOWER() What describes the 'heap table' structure's approach to managing free space after row deletion? Tracks free space as a linked list for future inserts What is the purpose of an ER Diagram? To visually represent the data model of a system What is the main advantage of a sorted table? Optimal for queries that read data in sort order What does the cardinality of a relationship indicate? The maximum and minimum number of entity instances that can be involved in a relationship What is a primary feature of relational databases? Tables Which constraint ensures uniqueness in a table's column? PRIMARY KEY What does SQL stand for? Structured Query Language The MySQL Enterprise Edition includes components for: High-end commercial installations, like backup and security What is the main purpose of the MySQL Monitor in the Enterprise Edition? To collect and display system performance information Which function would you use to find the least/lowest value in a set? MIN() In which normal form are all non-key attributes fully functionally dependent on the primary key? 3NF The GROUP BY statement is used to: Aggregate rows of data based on a common criteria The storage engine in MySQL is also known as: Storage manager What describes data in terms of scope, format, and access? Data Characteristics What does the Audit component in MySQL Enterprise Edition track? All database changes, including time and user details What is the result of a SELECT statement? A set of tuples Which SQL command is used to create a new table? CREATE TABLE What is a significant disadvantage of table clusters for certain queries? Performs poorly for joins on non-cluster key columns How does a hash table determine the bucket containing each row? Using a hash function and hash key Which term describes the process of denormalization? Merging Tables A column in Table B has been indexed? Which action would cause the index to be updated? A row is deleted from Table B What does the query processor layer in MySQL do? Compiles queries into low-level instructions To calculate the square root of a number in SQL, you would use: SQRT() What is an attribute in the context of ER modeling? A descriptive property or characteristic of an entity To combine two or more columns or strings into a single string in SQL, you would use: CONCAT() Which of the following best describes the role of a database administrator? Designs the physical layout of data, Secures the database against unauthorized access , Monitors the database performance and makes adjustments to optimize it Which normal form removes partial dependencies? 2NF Which SQL statement is used to remove rows of data from a database? DELETE What is the purpose of the ON clause in SQL joins? Specifies the condition for the join between the two tables Which of the following best describes a strong entity? An entity that has a unique identifying attribute The LIKE operator is used to: Search for a specified pattern in a column To find the number of non-NULL rows in a column, you would use: COUNT() Which statement about NoSQL databases is true? They are optimized for big data In ER modeling, what describes the relationship between a salesperson and an office space/cubicle? One-to-One In which type of table is no specific order imposed on rows? Heap table Which symbol represents a one-to-many relationship in ER Diagrams? A crow's foot Which SQL function returns the current date? CURDATE()