change partitioned table in sql2012

http://blogs.msdn.com/b/psssql/archive/2013/03/19/sql-server-2012-partitioned-table-statistics-update-behavior-change-when-rebuilding-index.aspx

If a table is partitioned, ALTER INDEX REBUILD will only update statistics for that index with default sampling rate.  In other words, it is no longer a FULLSCAN.  This is documented in http://technet.microsoft.com/en-us/library/ms188388.aspx.  But lots of users do not realized that.  If you want fullscan, you will need to run UPDATE STATISTCS WITH FULLSCAN.   This change was made because we started to support large number of partitions up to 15000 by default.