[UPHPU] Star and Snowflake Schemas

[Dave Smith]

Daniel C. wrote:
> Just wondering if anyone here has experience implementing star or
> snowflake schemas in an RDBMS, and (assuming someone has), whether
> you'd be willing to tell me a bit about them.  I understand the
> problems they're designed to solve, but I haven't been able to find a
> good example of an implementation of either schema.

I read this post and thought, "Wow. I should check out this new DB 
principle that apparently is called 'star' and 'snowflake' schema." It 
turns out that these are two common and simple RDBMS concepts if my 
googling has proved accurate. I just had never named them this way 
before. I'd imagine that 99% of all database schema are of the "star" or 
"snowflake" variety. Here's an example of a star schema:

Customer Table
- ID
- Last name
- First name

Address Table
- Customer ID
- Address Line 1
- Address Line 2

Purchase History Table
- Customer ID
- Item ID
- Purchase Date

Customer Credit Card Table
- Customer ID
- CCN
- Billing Name
- Billing Address

In this example, the Customer Table would be at the center of the star 
and the other 3 tables would be around the perimeter. May I inquire what 
prompted this question?

You could probably find implementations of these schema types in any 
blogging software with a relational database backend. OSCommerce comes 
to mind also, as does a myriad of other software.

--Dave