With the exception of different set options, a procedure will only have a single plan in cache at a time, so measured more likely in kB than GB.
Query sys.dm_exec_cached_plans, cross apply to sys.dm_exec_query_plan and filter on the object id.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
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