title: SQL Server - timeout removing clustering from primary key
body: <p>I have a large table with at the moment 2500000 rows in sql server 2012. The primary key is listed as <code>Create as clustered: Yes</code> and since the primary key is a <code>uniqueidentifier</code> I would like to change it to be non-clustered for starters (and then at some time in the future, cluster on the date column instead).</p>
  
  <p>The problem is that this times out. How can it be slow to disable clustering of an index?
  And what can I do to speed this up and finish before the timeout, except increasing the timeout to 24 hours for this operation?</p>