Does the number of columns affect query performance?

Question

CASE 1: I have a table with 30 columns and I query using 4 columns in the where clause.

CASE 2: I have a table with 6 columns and I query using 4 columns in the whe

Answer 1

There will be no performance difference based on the column position. Now the construction of the table is a different story e.g. number of rows, indexes, number of columns etc.

The scenario you are talking about where you are comparing the position of the column in the two tables is like comparing apples to oranges almost, because there are so many different variables besides the column position.