too much bandwidth

[Administrator]

hi,

in grids and grouping grids bound to datasets and dataviews, how much prefetching do they do. we noticed that over internet connections things get slow. how can we tweak this, hopefully without having to go virtual.

tia

[Administrator]

I think Ado.Net normally uses a disconnected architecture. So, when you do a DataAdapter.Fill the whole request is processed and stored locally, and is used in a disconnected manner until you do an update. Our grids play no role in this. They are just use the disconnected result set in a strictly disconnected manner.

So, once a dataset has been retrieved, I do not think there should be further loads on your database until you call dataAdapter.Update. But I may be missing something here.

[Administrator]

i did suspect the fill, but what if a query is 1 GB, over the internet we''ll be be sitting there an hour at least. i''m just throwing this out there, let me know if you see a fix. would a virtual grouping grid be possible? very difficult i''d imagine.

thanks

[Administrator]

The only way I would know to handle this is to adjust the query so you grab bite-size chunks, allowing you to page your requests. Normally I think people load a separate dataset and then merge the newly retrieved dataset with their already downloaded one. This is all independent of the grid. You can use grid events to try to let you know when you need to fetch another page, but it would be the Frmework actually getting the data and merging it into your dataset. And you would have to manage the paging criteria in some manner.

I do not think there would be any advantage to using a virtual gridcontrol in this situation. You would still have to manage the external data some how.