Here is the data

Table product

pd_id pd_name
----------- ----------------------------------------
1 Diet Coke - 6pack
2 Diet Coke - 2liter

Table product_price

pr_id pd_id pr_price pr_effdate
----------- ----------- --------------------- ---------------------------
1 1 .9900 1999-07-01 00:00:00.000
2 1 1.0500 1999-10-01 00:00:00.000
3 1 .7500 1999-10-11 00:00:00.000
4 1 1.0500 1999-10-15 00:00:00.000
5 2 1.4900 1999-07-01 00:00:00.000
6 2 .9900 1999-10-11 00:00:00.000
7 2 1.4900 1999-10-15 00:00:00.000