Performance Tuning with SQL Server Dynamic Management Views

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Chapter 7: OS and Hardware Interaction
active your cache is for SQL plans, we can filter on type, either CACHESTORE_SQLCP or
CACHESTORE_OBJCP, as shown in Listing 7.28.
SELECT name ,
type ,
entries_count ,
entries_in_use_count
FROM sys.dm_os_memory_cache_counters
WHERE type IN ( 'CACHESTORE_SQLCP', 'CACHESTORE_OBJCP' )
--ad hoc plans and object plans
ORDER BY name ,
type
Listing 7.28: Investigating the use of the plan cache.
On my test laptop, this returns the following output:
name type entries_count entries_in_use_count
-------------- ------------------ -------------------- --------------------
Object Plans CACHESTORE_OBJCP 22 0
SQL Plans CACHESTORE_SQLCP 44 2
We can run some ad hoc SQL, such as select *from sys.objects, and then rerun
Listing 7.18, in order to see a new entry added to the SQL Plans cache:
name type entries_count entries_in_use_count
-------------- -------------------- -------------------- --------------------
Object Plans CACHESTORE_OBJCP 22 0
SQL Plans CACHESTORE_SQLCP 46 7
Notice that the entries_count for SQL Plans has increased by two, one for the
counters query, and one for the ad hoc SQL (it might increase more due to other background
processes) but the use count was not incremented. This, of course, is because the