Plan Cache: The portion of the memory pool allocated to store Query execution Plan For how much memory is allocated for Plan Cache in different version of SQL server, please refer to my blog: - Understanding Query Plan Cache in SQL 2005 SP2 - why it...

Query execution plan gets stored in Plan Cache - the portion of the memory pool allocated for storing execution plans. There is a very good blog written by SQL Programmability team on why Query Plan Cache behavior changed in SQL 2005 SP2 vs. SQL 2000...

I came across this link - http://technet.microsoft.com/en-us/library/ms143432(SQL.100).aspx .  Its amazing to see the max capacity specification for SQL Server.    These are for SQL Server 2008, but they haven't changed from SQL Server...