query for single use ad hoc queries in the plan cache

gistfile1.sql

SELECT [text], cp.size_in_bytes, plan_handle
FROM sys.dm_exec_cached_plans AS cp
  CROSS APPLY sys.dm_exec_sql_text(plan_handle)
WHERE 
    cp.cacheobjtype = N'Compiled Plan'
AND cp.objtype = N'Adhoc'
AND cp.usecounts = 1
ORDER BY cp.size_in_bytes DESC;