You should perform the following tasks after updating :

• Upgrade Database Compatibility Level The database compatibility level needs to be manually changed on the 2014 instance
• Run DBCC CHECKDB WITH DATA_PURITY
• Checks for invalid data values based on column data type Run DBCC UPDATEUSAGE
• Corrects page count inaccuracies to reflect accurate information when using sp_spaceused
• Run sp_refreshview
• Ensures that views are up to date
• Update Statistics
• Brings database statistics are up to date to allow the query optimizer to choose the best query plan
• Take a Full Backup of the Database
• Make sure you can recover the database with all of the migration efforts
• Monitor Performance between Cardinality Estimators

It’s important to note: SQL Server 2014 received a major overhaul of the cardinality estimator. For the vast majority of queries, performance will improve due to better row estimations. However, in some scenarios estimations could be worse which may result in performance degradation. It’s important to monitor most commonly used queries to see if any performance degradation is resulting from poor estimations. It is possible to utilize the old cardinality estimator by leveraging a database compatibility level of 110 or lower or by leveraging trace flag 9481.

You should perform the following tasks after updating :

1. Upgrade Database Compatibility Level
   • The database compatibility level needs to be manually changed on the 2014 instance
2. Run DBCC CHECKDB WITH DATA_PURITY
   • Checks for invalid data values based on column data type
3. Run DBCC UPDATEUSAGE
   • Corrects page count inaccuracies to reflect accurate information when using sp_spaceused
4. Run sp_refreshview

• Ensures that views are up to date

5. Update Statistics

• Brings database statistics are up to date to allow the query optimizer to choose the best query plan

6. Take a Full Backup of the Database
7. Make sure you can recover the database with all of the migration efforts
8. Monitor Performance between Cardinality Estimators

It’s important to note: SQL Server 2014 received a major overhaul of the cardinality estimator. For the vast majority of queries, performance will improve due to better row estimations. However, in some scenarios estimations could be worse which may result in performance degradation. It’s important to monitor most commonly used queries to see if any performance degradation is resulting from poor estimations. It is possible to utilize the old cardinality estimator by leveraging a database compatibility level of 110 or lower or by leveraging trace flag 9481.