DBCC Trace Flags 2562 and 2549

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Erin Stellato and Jonathan Kehayias from sqlskills reached out asking for clarification of trace flags 2562 and 2549 behavior.  Trace flags 2562 and 2549 are documented in knowledgebase article: https://support.microsoft.com/en-us/kb/2634571and the blog post https://blogs.msdn.microsoft.com/bobsql/2016/06/03/sql-2016-it-just-runs-faster-dbcc-scales-7x-better/highlights the SQL 2016 DBCC performance improvements.


For SQL Server 2008, 2012 and 2014 the trace flag behavior remains the same. For SQL Server 2016 the trace flags are available but the behavior may be altered by the design changes.

Trace flag 2549 is used to change how DBCC sees the volume layout of the database.   The SQL Server 2016 design change uses the