D426 Data Management Foundations - Set 1 - Part 1

Correct Answer: First Normal Form (1NF)

First Normal Form (1NF) ensures that every cell contains exactly one value and that the table has a primary key. This is the most basic form of database normalization.

Correct Answer: NOT NULL

The NOT NULL keyword is used to ensure that a column does not accept NULL values. It is added in the column definition during table creation.

Correct Answer: LEFT JOIN

A LEFT JOIN selects all rows from the left table and only the matching rows from the right table. Rows from the left table without a match in the right table will have NULLs in the columns from the right table.

Correct Answer: EQUIJOIN

An EQUIJOIN is used to compare columns using the = operator in SQL. It is the most common type of join where two tables are joined based on equality between specified columns.

Correct Answer: Primary Key

A Primary Key uniquely identifies each row in a table and must always have unique, non-NULL values.

Correct Answer: Physical Design

Physical Design specifies how the database tables are organized on storage media, including indexes and partitions, to optimize query performance.

Correct Answer: Dense Index

A Dense Index contains an entry for every row in the table, unlike a Sparse Index, which contains entries for only certain rows or blocks.

Correct Answer: The number of times an entity can be related to another entity

Cardinality refers to the maximum and minimum number of times one entity can be related to instances of another entity in a relational database.

Correct Answer: CREATE TABLE

The CREATE TABLE statement is used to define and create a new table by specifying its column names, data types, and constraints.

Correct Answer: One-to-Many

A One-to-Many relationship is established when a foreign key in one table refers to the primary key in another table, allowing multiple rows in the first table to relate to a single row in the second.

Correct Answer: MIN()

The MIN() function returns the smallest value from a set of rows in SQL. It is often used to find the minimum value in a numeric column.

Correct Answer: Deletes all rows from a table

The TRUNCATE statement in SQL is used to remove all rows from a table but keeps the table structure intact for future use.

Correct Answer: Constraint

Constraints are rules defined on columns to enforce data integrity, ensuring that only valid data is inserted, updated, or deleted.

Correct Answer: It is automatically assigned a unique number for each row.

An AUTO_INCREMENT column automatically generates a unique, sequential number for each new row inserted into the table.

Correct Answer: Third Normal Form (3NF)

Third Normal Form (3NF) requires that all non-key columns depend on the primary key and no other non-key column.

Correct Answer: WHERE

The WHERE clause filters the results returned by a query based on the specified condition, such as comparing column values.

Correct Answer: Sparse Index

A Sparse Index stores entries only for certain blocks of a table, making it more efficient for larger datasets where not every row needs to be indexed.

Correct Answer: INNER JOIN

An INNER JOIN returns only the rows that have matching values in both the left and right tables. It excludes rows that do not have matches in either table.

Correct Answer: To refer to the primary key in another table

A foreign key in a relational database is used to create a link between two tables by referencing the primary key in another table.

Correct Answer: SUM()

The SUM() function adds together all the values in a specified column and returns the total.