I've been researching what Natural and Surrogate keys are
in the web and really can't find a straight and clear
answer. Does anyone want to take a crack at it?

A surrogate key is a unique identifier assigned to a entity in a dimension
table. it has no real-world meaning.
A natural key identifies an entity in the real-world

Its probably better explained with an example.
A bank may have a data warehouse relating to all its customers - for
argument's sake lets say they identify all those users by their account
number (call it account_no). When the custotmers are loaded into the
appropriate dimension table they will be assigned a number (call it CustID)
that uniquely identifies that record. If you are modelling your customer
dimension as a type-2 dimension then you may find that you will later load a
second record in for a particular user. That record would contain the same
account_no but would have a new CustID assigned.
[Don't worry about that a type-2 dimension is for now.]

In this example account_no is the natural key and CustID is the surrogate key.


Thats my interpretation of them anyway. Hope I haven't baffled you.

Regards
Jamie Thomson
http://www.conchango.com


"anonymous (AT) discussions (DOT) microsoft.com" wrote:

OK, so you are saying that the surrogate key is basically
an identity that really has no meaning, no rhyme or
reason or relationship to anything?

Correct. It has no real-word meaning.

Regards
Jamie Thomson

"anonymous (AT) discussions (DOT) microsoft.com" wrote:

World not word!!!

"Jamie" wrote: