title: How to write a listagg on Redshift?
body: <p>For sample data as below,</p>
  
  <pre><code>Col1 Col2
  1    A
  1    B
  1    C
  2    A
  2    B
  </code></pre>
  
  <p>the output I am looking for is</p>
  
  <pre><code>COL1 COL2
  1    A B C
  2    A B
  </code></pre>
  
  <p>This can be done using LISTAGG on Oracle or recursive queries on other DBs but Redshift doesnt support both.</p>
  
  <p>How do I achieve this on Redshift</p>