title: Do I need a primary key with an Oracle identity column?
body: <p>I am using Oracle 12c and I have an <code>IDENTITY</code> column set as <code>GENERATED ALWAYS</code>.</p>
  
  <pre><code>CREATE TABLE Customers
  (
     id            NUMBER GENERATED ALWAYS AS IDENTITY,
     customerName  VARCHAR2(30) NULL,
  
     CONSTRAINT "CUSTOMER_ID_PK" PRIMARY KEY ("ID")
  );
  </code></pre>
  
  <p>Since the ID is automatically from a sequence it will be always unique.</p>
  
  <p>Do I need a PK on the ID column, and if yes, will it impact the performance?
  Would an index produce the same result with a better performance on <code>INSERT</code>?</p>