The ALL subquery performs which operation?

Solution (By Examveda Team)

This question is about how the ALL keyword works in MySQL subqueries. A subquery is a query nested inside another query.

The ALL keyword is used to compare a value with every value in the result set of the subquery.

Let's break down the options:
Option A: row - This is partially correct. The ALL keyword compares a value against all rows of the subquery's result set.
Option B: column - The ALL keyword doesn't directly compare columns. It compares values within rows.
Option C: table - This is incorrect. The ALL keyword operates on the result set of a subquery, not the whole table.
Option D: database - This is incorrect. The ALL keyword's scope is limited to the subquery's result set.

In essence, the ALL subquery performs a comparison of a value to all the rows produced by the subquery.

So, the best answer is Option A: row.