1. If you want to immediately release the open connection, you should try to close it:
Code:
Public Sub openMyRecordset()
Dim db As DAO.Database
Dim qd As DAO.QueryDef
Dim rs As DAO.Recordset

Set db = CurrentDb
Set qd = db.CreateQueryDef("")

qd.Connect = connString
qd.SQL = "usp_test"

Set rs = qd.openRecordset

rs.Close
qd.close

db.Close

Set rs = Nothing
Set qd = Nothing
Set db = Nothing
End Function
2. For in-depth explanation on how the connection pooling mechanism works, see: https://msdn.microsoft.com/en-us/lib...ConnectionPool