Reassert uniqueness by pin and doc_no in default.vw_pin_sale

[wrridgeway]

default.vw_pin_sale is supposed to be unique by pin and doc_no when mutisales are included and by doc_no when they are not. This still holds true when multisales are excluded, but no longer seems to be the case when they're included. I'm not sure when this became the case since many of the sales in question are from over a decade ago.

This issue is propegating from iasworld.sales. We can see that

select
    parid as pin,
    instruno as doc_no,
    price as sale_price,
    saledt as sale_date
from iasworld.sales
where instruno = '1202334001'
    and cur = 'Y'
    and deactivat is NULL

yields four rows spread over two different dates, all with the same price and doc_no, across two pins. This shows up in default.vw_pin_sale, which shouldn't be the case - we should only get two rows here, one for each pin for a sale on 1/1/2011.

pin	doc_no	sale_price	sale_date
04324020170000	1202334001	2500000	12/1/2011
04324020170000	1202334001	2500000	1/1/2011
04324020240000	1202334001	2500000	1/1/2011
04324020240000	1202334001	2500000	12/1/2011