Which data validation technique prevents invalid data from being entered into the database by checking it against predefined rules?
Data Transformation
Data Masking
Data Scrubbing
Check Constraints
What is the primary goal of database normalization?
Minimizing storage space
Reducing data redundancy and anomalies
Improving query performance
Enhancing data security
In which scenario might denormalization be considered acceptable in database design?
To increase data redundancy
To enforce strict data integrity
To simplify the database schema
To improve query performance by reducing joins
To change the data type of a column in an existing table, which clause should be used with the ALTER TABLE statement?
CHANGE COLUMN
TRANSFORM COLUMN
MODIFY COLUMN
UPDATE COLUMN
In a Star Schema, what is the central table called that contains the key performance indicators (KPIs)?
Dimension Table
Fact Table
Entity Table
Lookup Table
Which of the following is NOT a good practice when designing a simple schema for a single entity?
Defining primary keys to uniquely identify each row
Storing redundant data in multiple columns
Choosing appropriate data types for columns
Using descriptive names for tables and columns
Which of the following is NOT a valid SQL data type for storing numerical values?
FLOAT
VARCHAR
INTEGER
DECIMAL
Which SQL statement is used to create a new table in a database?
CREATE TABLE
INSERT TABLE
NEW TABLE
MAKE TABLE
What is the role of cardinality in an ER diagram?
It specifies the name of the relationship between entities
It indicates the number of instances of one entity that can be associated with instances of another entity
It defines the data type of an attribute
It determines the primary key of an entity
Referential integrity ensures that...
all columns in a table have unique values.
data is backed up regularly.
queries are optimized for performance.
relationships between tables remain consistent.