title: Comparing records of tables based on composite key
body: <p>I have a job to refresh a look up table data for which I need help. I have 2 tables with data, one is the existing version (table1) and the other is the new version (table2). The primary key for each of the tables is a composite key. I know there is a different number of rows in each one and I need to find out the differences. Let's assume that the 2 columns part of the composite primary key to be named column1 and column2.</p>
  
  <p>Typically, in the "normal" primary key set-up, I would just look for primary key values NOT IN the list of primary keys from the other table. But I don't know how to do this with a composite primary key.</p>
  
  <p>I found a similar thread for SQL Server but that doesn't seem to work in my case, not sure if I'm doing something wrong.</p>
  
  <p><a href="https://stackoverflow.com/questions/2435869/how-can-i-compare-rows-from-2-tables-that-have-composite-primary-keys">How can I compare rows from 2 tables that have composite primary keys?</a></p>
  
  <p>Can someone help me compare the rows from these two tables in Oracle/PostgreSQL?</p>