You can also reduce database read time by eliminating unnecessary
ORDER BY clauses in your SQL queries. For example, consider
the following SELECT statement designed to retrieve the product
name and price when given a product number.
SELECT product_name, price
WHERE product_num = "123456789"
ORDER BY product_name
Assuming the product number is unique for all products in the catalog,
this query only returns a maximum of one record. Even
though sorting 0 or 1 records should be very quick, the ORDER
BY clause is actually redundant. When this query is executed
hundreds or thousands of times for different products,
this redundant overhead can add up. Eliminate this type of redundancy.