Article ID: 2953452 - View products that this article applies to.
After you upgrade to Microsoft SQL Server 2014, you notice a decrease in performance in Microsoft Team Foundation Server (TFS) 2013 Update 2.
For example, you notice that Work Item Tracking slows down. When this occurs, it takes significantly longer to open and change work items if you have many fields that are set to syncnamechanges=true.
Additionally, if you have many Team Project collections in the affected TFS instance, you notice the following issues:
These issues occur because the hardware requirements for SQL Server 2014 are greater than those for ealier versions of SQL Server.
The Work Item Tracking performance issue occurs because several views that are used by Work Item Tracking contain one or more joins to the Constants table for each field that includes this attribute. The new cardinality estimator in SQL Server 2014 sometimes determines incorrectly that these joins will return more than one row. When there are many of these joins, SQL Server can miscalculate the total number of rows that are returned by the views as a very large number. Therefore, the program dtermines incorrectly that it must spend lots of time to optimize the query plans that involve the views.
To work around the overall performance issue, use the following methods:
For a description of trace flag 8032, see the following Microsoft TechNet topic:
Trace Flags (Transact-SQL)
Note This information relates to SQL Server 2012 but also applies to SQL Server 2014.
For more information about the Work Item Tracking syncnamechanges attribute, see the following MSDN article:
Enable Synchronization of Person-Name Custom Fields
For more information about how to view or change the compatibility Level of a database, see the following TechNet topic:
View or Change the Compatibility Level of a Database