New cardinality estimator (SQL Server 2014) is way off

Question

I have a data warehouse database and I\'m facing problems with the new cardinality estimator of SQL Server 2014.

After upgrading the database server to SQL Server 2014 I

Answer 1

I wonder if you are running into this issue around multicolumn selectivity estimates:

http://www.sqlskills.com/blogs/kimberly/multi-column-statistics-exponential-backoff/

it seems that there are still some quirks with the new CE try also using TF 4137 as outlined and see if that helps.

finally make sure you are on the latest CU and are running with TF 4199 to blanket enable all query optimizer fixes as always test this in a non-production environment if possible first and be mindful of regressions in other queries when enable settings globally