title: How can I fix "Snapshot isolation transaction aborted due to update conflict"?
body: <p>I see an error message related to transaction isolation levels. There are two tables involved, <em>first</em> one is updated frequently with transaction isolation level set to <strong>SERIALIZABLE</strong>, the <em>second</em> one has a foreign key on <em>first</em> one.</p>
  <p>Problem occurs when doing insert or update of the <em>second</em> table. Once in few hours I get the following error message:</p>
  <blockquote>
  <p>Snapshot isolation transaction aborted due to update conflict. You cannot use snapshot isolation to access table 'dbo.first' directly or indirectly in database 'DB' to update, delete, or insert the row that has been modified or deleted by another transaction. Retry the transaction or change the isolation level for the update/delete statement.</p>
  </blockquote>
  <p>I don't set transaction isolation level when inserting or updating <em>second</em> table, also I ran command <strong>DBCC USEROPTIONS</strong> and it returns read_committed.</p>