sequence instead of composite key - whats better

[malva]

Does anyone have any information on the pros and cons on using artificial keys instead of large composite keys. I have been told in Oracle there is no performance hit, but I am not a believer without supporting information.

 

[carp]

The pros of an artificial key are (1) they can be populated automatically, (2) you don't have to worry about non-unique values (provided you're populating via a sequence, (3) you don't have to worry about NULL values, and (4) foreign keys only have to reference one column instead of multiple columns.
The cons are (1) they impose additional storage requirements.

My personal take - if you have one or more columns that will work as a PK, use them.