TMS RemoteDB — does it support partial / on-demand fetching for large datasets?

[Tom]

Hi,

We're using TXDataset bound to a DevExpress cxGrid (with DataController.GridMode := True) against Firebird via TMS RemoteDB / Sparkle. With FIBPlus, GridMode kept a server-side cursor alive and only fetched the specified rows (100); with RemoteDB the full result set appears to be returned on the first fetch (4,700 rows for my items list).

Is there a configuration on TXDataset, or the underlying FireDAC connection that enables on-demand row fetching across HTTP requests? Or is full materialization a fundamental constraint of the protocol, and we should be looking at application-level pagination instead?

Thanks, Tom

[wlandgraf (Wagner Landgraf)]

@Tom

Or is full materialization a fundamental constraint of the protocol, and we should be looking at application-level pagination instead?

Correct.
The point (one of them) of RemoteDB is exactly to prevent having server-side cursors open, to avoid stateful communication and minimize issues with slow or intermittent internet communication.

So yes, RemoteDB always fetch all data and always close server-side cursor. Pagination must be done at application level, by retrieving parts of data using specific SQL command constructions like LIMIT and/or TOP.