A data analyst wants to generate the most data using tables from a database. Which of the following is the best way to accomplish this objective?

A FULL OUTER JOIN is the best method to generate the most data because it returns all rows from both tables involved in the join. It combines the functionality of both LEFT and RIGHT OUTER JOINs. When a row from one table does not have a matching row in the other, the join still includes the row and fills the columns from the non-matching table with NULL values. This ensures that no data is excluded from either table, resulting in the largest possible dataset from the combination.

A. INNER JOIN: Incorrect. This join is the most restrictive, returning only the rows where the join condition is met in both tables, typically producing the fewest results.
B. LEFT OUTER JOIN: Incorrect. This join returns all rows from the left table but only matching rows from the right, potentially omitting non-matching rows from the right table.
C. RIGHT OUTER JOIN: Incorrect. This join returns all rows from the right table but only matching rows from the left, potentially omitting non-matching rows from the left table.

1. Silberschatz

A.

Korth

H. F.

& Sudarshan

S. (2020). Database System Concepts (7th ed.). McGraw-Hill. In Chapter 4

Section 4.2.3 "Outer Join"

the text explains that a "full outer join is the union of the results of the left and right outer joins

" preserving all tuples from both relations.

2. PostgreSQL Documentation. (2023). 7.2. Tables and Joins. In PostgreSQL 16 Documentation. Retrieved from https://www.postgresql.org/docs/16/queries-table-expressions.html#QUERIES-JOIN. Section 7.2.2

"Join Types

" describes the FULL OUTER JOIN as including all rows from both joined tables

with null values used for non-matching columns.

3. Stonebraker

M.

& Hellerstein

J. M. (2010). Lecture 2: Advanced SQL. MIT OpenCourseWare

6.830 Database Systems. The lecture notes describe the FULL OUTER JOIN as the union of the LEFT and RIGHT outer joins

which by definition encompasses all rows from both tables.