The ALL subquery performs operations on . . . . . . . .

Solution (By Examveda Team)

This question asks about the ALL subquery in MySQL. A subquery is a smaller query that sits inside a larger query.
The ALL subquery compares a value from the main query to every value in the result set of the subquery.
Let's break down the options:
Option A: row - A row is a horizontal collection of data in a table. The ALL subquery doesn't operate on entire rows; it compares single values.
Option B: column - A column is a vertical collection of data in a table. The ALL subquery works by comparing a value in the main query to each value in a specific column of the subquery's result set.
Option C: table - A table is a structured collection of data. The ALL subquery operates on values within a specific column of a table, not the entire table.
Option D: database - A database is a collection of tables. The ALL subquery doesn't work at the database level.
Therefore, the correct answer is Option B: column.
The ALL subquery compares a value to all the values in a specific column returned by the subquery.