When working on a multidimensional design, every fact table within scope should be handled with care. In an ideal world, each low-level fact table represents the metrics related to a business event.

The column (field) in a relational database that uniquely identifies the row in the table. For example, account number is often a primary key. A "composite primary key" or "super key" is made up of ...

One of the principles within relational theory is that each entity’s row or tuple be uniquely identifiable. This means the defined structure includes some combination of attributes whose populated ...

All documents in a MongoDB collection have a primary key dubbed _id. This field is automatically assigned to a document upon insert, so there’s rarely a need to provide it. What’s interesting about ...

Every JPA entity has a primary key, but some entities have more than one value as their primary key. In this case, you need to use a composite key. This Java tip introduces you to using composite keys ...

MySQL table primary keys and unique indexes prevent multiple rows with the same index from being added to the table. If you try to insert a duplicate row with a ...