Oracle Primary Key, Unique Key, Unique Index
Posted on 2011-05-09
I assume he rationale for defining a Unique Index vs Primary Key or Unique Key is the Unique Index allows column values of NULL.
What are the reasons for defining a Unique Key with or without defining matching Primary Key columns? Or defining both with some or all different columns?
I am to update an existing packages that updates Oracle table data based on unique columns only. This package treats tables with Primary Key vs Unique Key completely differently, and I cannot see a reason for this different treatment.