Examine the following table and decide how to make it conform to the rule of the 2nd Normal Form:

The business has 30 stores in MD and DC. Order_IDs (Primary Key) are generated uniquely and sequentially across the 30 stores. For example, an Order_ID value of '000011' is unique across all stores and customers.

Question

Examine the following table and decide how to make it conform to the rule of the 2nd Normal Form:

The business has 30 stores in MD and DC. Order_IDs (Primary Key) are generated uniquely and sequentially across the 30 stores. For example, an Order_ID value of '000011' is unique across all stores and customers.

BlackTom AI · Accepted Answer

To evaluate how to bring the RECEIPT table into 2NF, we first restate what the table contains and what 2NF requires. The RECEIPT table shows Order_ID (PK), Customer_ID, Store_ID, Store_location, Date, Paid. The potential issue is a transitive dependency: Store_location is dependent on Store_ID, but Store_ID is not part of the primary key, so a non-key attribute (Store_location) depends on another non-key via Store_ID.

Option A: Delete the attribute 'Store_ID'. By removing Store_ID you erase the link to the store entity and lose the normalization opportunity. This does not resolve the underlying transitive dependency, and it would degrade data integrity by removing a necessary foreign key reference.

Option B: Nothing, it's already in 2NF. This claim is unlikely because the presence of Store_location depending on Store_ID introduces a transitive dependency (Store_location depends on Store_ID, which is not a key attribute itself). Therefore, the table is not in 2NF as written.

Option C: Move the attributes 'Customer_ID' and 'Store_ID' to create a bridging entity. A bridging (junction) table is typically used to model many-to-many relationships. Here, Customer_ID and Store_ID are already foreign keys; creating a separate bridge for them would be unnecessary unless there’s a many-to-many relationship between customers and stores in receipts. This approach adds complexity without clearly addressing the transitive dependency involving Store_location.

Option D: Move the attributes 'Store_ID' and 'Store_location' to a new table, STORE, and create a relationship between the RECEIPT table and the STORE table. This option directly decomposes the store-related data: STORE would hold Store_ID and Store_location, removing Store_location from RECEIPT. RECEIPT would then reference STORE via Store_ID. This eliminates the transitive dependency because Store_location is now stored in a separate entity that Store_ID uniquely identifies, aligning with 2NF rules.

In summary, the core issue is the transitive dependency of Store_location on Store_ID within RECEIPT. Creating a separate STORE table for Store_ID and Store_location and linking RECEIPT to STORE cleanly removes this dependency, satisfying 2NF. The other options either discard essential data, misapply normalization concepts, or fail to address the dependency structure appropriately.

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The process of Normalization is primarily about:

Which of the following is NOT something normalization is trying to do?

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