Synchronous: This is useful if you have all the data that need to be send to client with you already and want to put the data in DataSource so that it can be send to the clients in chunks. The DataSource session takes in a list of objects that you want sent to the client and returns you a DataChunk object, which contains the first chunk of data to be send to the client. If the List of data could fit in one chunk, then the session doesn't even create a DataSource, it just returns you the chunk. Otherwise a DataSource is created with the data, which can be polled later for additional chunks. The DataSource will be closed so that no more data can be added.

Asynchronous: In this case, you haven't got your data yet. You want to submit a task to get the data in a background thread and have the data returned to the client later. We leverage the capabilities of Executor framework provided by Java.(for more details refer JavaDoc of Executor) To create an asynchronous DataSource, the DataSource session takes a DataSourceTask which will be run by in a background thread sometime in the future. It returns a DataSourceFuture object, so that you have a way to access the DataSource information.

Disabled: Not DataSource enabled