You can modify the column names in the output with the AS clause. For example, to shorten the column names and show them without quotes, run the following query:

    SELECT *
FROM SALES_DATA
PIVOT (
    SUM(SALES_AMOUNT) -- Aggregation function
    FOR PRODUCT IN ('PRODUCT_A', 'PRODUCT_B', 'PRODUCT_C')
) as p(data_s,PRODUCT_A, PRODUCT_B, PRODUCT_C);