got it........thank you so much
[quoted text, click to view] "Bin Song, MCP" <anonymous@discussions.microsoft.com> wrote in message
news:0BE21B7A-2DB9-49F6-B6A5-5DF6DC10F110@microsoft.com...
> If you do use a dataset, your next choice is whether you want to recreate
it with each round trip. You have two options:
>
> Each time the page is processed, create an instance of the dataset and
fill it. When page processing is finished and the page is sent to the
browser, the dataset is discarded.
[quoted text, click to view] > Create and fill the dataset once (typically, the first time the page
runs). Then save the dataset in a way that you can retrieve it with each
subsequent round trip.
[quoted text, click to view] > Creating the dataset each time means that with each round trip ¡X
effectively, each time the user clicks a button on your page ¡X you execute
a query or stored procedure against the data source. For example, you might
have a Web Forms page where the user wants to page through data. If you
create the dataset each time, the Web Forms page executes a query against
the data source to get the next set of records to display.
[quoted text, click to view] >
> Tip Remember to always minimize data transfer. Whenever practical, use
selection criteria to reduce the number of records you need on a page.
> If you save and restore the dataset, on the other hand, you do not need to
go back to the source just to get a few more records. However, saving the
dataset has a number of drawbacks. An important one is that the dataset
consumes memory between round trips. If the dataset is very large, for
example, it can take considerable server memory to store it. If multiple
users create large datasets, you can quickly consume available server
memory. (An option is to store data in the page; for details, see the next
section.)
[quoted text, click to view] >
> Another potential drawback is that the dataset can get out of sync with
the data source, since you are not refreshing the dataset each time the user
clicks a button. If you are working with very volatile data (inventory data,
for instance), you might find it better for your application to recreate the
dataset with each round trip.
[quoted text, click to view] >
>