Degenerate Dimension

Experts:

Pardon me for this basic question. A degenerate dimension as I understand does not have a parent dimension (pls correct me if I am wrong) in the fact table. In that case is it repeated in the fact table?

For example if i have the following fact table

Productkey(FK)

Customerkey(FK)

Timekey(FK)

TicketNumber

All the first three (product,customer and Time) have dimensions while Ticketnumber has a orphan parent. In that case does its value get repeated in the fact table or is it usually a unique value?

Please explain.

Thanks

Ankith

Hello.

You are correct that ticketnumber do not have a parent and is a degenerate dimension.

If you sell the same ticket several times it can appear several times in the fact table. That is normally not the case. Think of a bus ticket, a cinema ticket or an airline ticket. For these later scenarios you will not see a repeted ticketnumber.

HTH

Thomas Ivarsson

|||

Hi Thomas:

Thank you very much for a lucid and beatiful explanation with examples. Appreciate it.

Best Regards

Ankith