AWS Certified Data Engineer Associate DEA-C01 Practice Question

To keep every row from web_clicks regardless of whether matching product metadata exists, the query must preserve all rows from the left (click) table and add columns from the right (product) table when matches are found. A left outer join does exactly that, returning NULLs for columns from dim_products when no corresponding product_id exists. An inner join would drop unmatched click events, a right join would keep only rows where a product exists, and a full outer join would add extra rows from dim_products that have never been clicked-none of which satisfy the stated requirement.