Setting the ActiveConnection property to Nothing should "close" the catalog. Associated collections will be empty. Any objects that were created from schema objects in the catalog will be orphaned. Any properties on those objects that have been cached will still be available, but attempting to read properties that require a call to the provider will fail.
Sub CloseConnectionByNothing()
Dim cnn As New Connection
Dim cat As New Catalog
Dim tbl As Table
cnn.Open "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source= c:\Program Files\Microsoft Office\" & _
"Office\Samples\Northwind.mdb;"
Set cat.ActiveConnection = cnn
Set tbl = cat.Tables(0)
Debug.Print tbl.Type ' Cache tbl.Type info
Set cat.ActiveConnection = Nothing
Debug.Print tbl.Type ' tbl is orphaned
' Previous line will succeed if this was cached
Debug.Print tbl.Columns(0).DefinedSize
' Previous line will fail if this info has not been cached
End Sub
Closing a Connection object that was used to "open" the catalog should have the same effect as setting the ActiveConnection property to Nothing.
Sub CloseConnection()
Dim cnn As New Connection
Dim cat As New Catalog
Dim tbl As Table
cnn.Open "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source= c:\Program Files\Microsoft Office\" & _
"Office\Samples\Northwind.mdb;"
Set cat.ActiveConnection = cnn
Set tbl = cat.Tables(0)
Debug.Print tbl.Type ' Cache tbl.Type info
cnn.Close
Debug.Print tbl.Type ' tbl is orphaned
' Previous line will succeed if this was cached
Debug.Print tbl.Columns(0).DefinedSize
' Previous line will fail if this info has not been cached
End Sub