The Re-compiles (Per Second) metric calculates the rate of re-compiles on your monitored instance, using the counter SQL Re-Compilations/sec from the SQL Server SQL Statistics counter object.
On SQL Server 2000 instances, this counter is available through sysperfinfo and represents the rate of batch re-compilations per second.
On SQL Server 2005 or later instances, this counter is available through sys.dm_os_performance_counters and represents the rate of statement-level re-compilations per second.
Typically, this metric value is low. A high re-compilation rate may be a sign of excessive re-compilation overhead. Causes of re-compiles include various events including schema changes, statistics updates, and explicit calls to WITH RECOMPILE. Excessive re-compilation impacts you server performance.