title: What is uuid ossp in postgres
body: <p>I've seen this in a migration</p>
  
  <pre><code>enable_extension 'uuid-ossp'
  </code></pre>
  
  <p>as far as I know uuid is a long unique string based on some RFCs, and this enable the db (in this case pg) to have a column type as a uuid</p>
  
  <p>my question is - Why is this type of column needed and not just a string column?
  is it to replace the regular integer id column and to have a uuid as the id instead?</p>
  
  <p>is there any advantage to use a uuid as the id instead of just having a string type column contain a uuid?</p>