If you want to change it, you need to do this on the client, as Remus already mentioned. The client is creating the connection pool.
You can specify the connection pooling properties in your connection string that you use to connect to SQL Server. The most important properties are:
- Pooling : which can be true or false - use pooling or not
- MinPoolSize : minimum size of connection pool; default is 10
- MaxPoolSize : maximum size of connection pool; default is 100
So if you want to enable pooling and have min. 20, max. 250 connections, you could use this connection string:
server=MyServer;database=MyDatabase;Pooling=True;Min Pool Size=25;Max Pool Size=250
For more details, see the MSDN docs or check out the Connection Strings web site.