DataTypeDictionary consistency and lifetime
Posted: 18 Jan 2018, 09:49
On the client side (C++),
I can get the structure definition of an ExtensionObject through calling the DataTypeDictionary that is an interface, i.e. a part of the Session.
Question: is the definition for any given DataTypeId constant over the lifetime of the session? Or can the server change a user defined data structure while keeping the session alive?
Use case: the client is monitoring a large user defined structure, and needs to get out a small number of its elements that it knows by name. Getting the structure definition and searching for the matching elements takes time. Can the client store the indices of the elements it is interested in when doing the first read, and just directly read the elements using the stored indices on all further data updates during the session?
I can get the structure definition of an ExtensionObject through calling the DataTypeDictionary that is an interface, i.e. a part of the Session.
Question: is the definition for any given DataTypeId constant over the lifetime of the session? Or can the server change a user defined data structure while keeping the session alive?
Use case: the client is monitoring a large user defined structure, and needs to get out a small number of its elements that it knows by name. Getting the structure definition and searching for the matching elements takes time. Can the client store the indices of the elements it is interested in when doing the first read, and just directly read the elements using the stored indices on all further data updates during the session?