Will the SQL Azure compatibility level affect performance?
I have a V11 database at compatibility level 100.
I have a V12 database at compatibility level 120.
a) What does 100 mean?
b) If I change the compatibility level from V11 to 110, would it have an impact on performance?
b) If I change the compatibility level on V12 to 110, would it affect performance?
source to share
You can read more about compatibility levels here . Basically, this is used for backward compatibility with SQL. To answer your question about efficiency, I would like to quote this paragraph from an MSDN article:
The compatibility level affects behavior only for the specified database, not for the entire server. The compatibility level provides only partial backward compatibility with earlier versions of SQL Server. Starting with compatibility mode 130, any new query plan affecting functions was added only to the new compatibility mode. This was done in order to minimize the risk of performance degradation during updates due to query plan changes. From an application perspective, the goal still needs to be at the latest compatibility level in order to inherit some of the new functionality, and to improve performance in the query optimizer space, but do so in a controlled manner.
Hope this helps! Silvia doomra
source to share