title: Unload all table from redshift to s3 - cpu usage
body: <p>The goal is to unload a few tables (for each customer) every few hours to s3 in parquet format</p>
  <p>Each table is around 1GB (CSV format), in parquet it is around 120MB</p>
  <p>The issue is when running 2-3 parallel unloads commands the cpu of the redshift nodes goes to 98%-100% in the cluster.</p>
  <p>This is the command I use:</p>
  <pre><code>unload ('select * from my_table')
  to 's3://test_bucket'
  iam_role 'my_arn'
  allowoverwrite
  format PARQUET;
  </code></pre>
  <p>I also tried to unload the data as CSV but the nodes also went to around 98-100% CPU.</p>
  <p>I would like to save a snapshot of the whole table (a few tables) every few hours and I must have all the columns so I have to use <code>select *</code>.</p>
  <p>Is there another approach I might take that would not raise my redshift CPU so high?</p>
  <p>The node type is <code>ra3.xlplus</code> with 4 nodes.</p>
  <p><a href="https://i.stack.imgur.com/foUTG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/foUTG.png" alt="enter image description here" /></a></p>