max number of records in dataset?

[Graeme]

Hi

Using Winforms, ado.net, MS Access connection, datagrid. Is there a max
number of records that can be handled? I will have about 50,000 and user
should be able to scroll thru all in the worst case.

Thanks
Graeme

 

[Miha Markic [MVP C#]]

16,777,216
However, you really shouldn't fetch that much data.
You might give a filter option to user and then use filter's data in sql
select statament.

 

[Mary Chipman]

That kind of data access in an application may have made sense when
the entire thing was in Access/Jet, because an Access front-end uses
keyset cursors to keep data fresh. It is not a good idea where
disconnected data is fetched and cached in Datasets. There is no such
thing as a keyset cursor in a Dataset to display refreshed data if a
row changes. Nobody can read fast enough to browse all 50,000 records
without the data getting stale. A better solution would be to
implement a query by form mechanism where only a limited subset of
rows are returned, allowing the users to narrow down their search
criteria and browse data in smaller, fresher, chunks. Think amazon.com
-- do they try to show you all of their books at once when you go to
the site?

-- Mary
MCW Technologies
http://www.mcwtech.com

 

[Graeme]

Thanks, but as I said, "worst case". I have implemented a number of subset
queries. Cheers, Graeme

 

[Bernie Yaeger]

Hi Graeme,

People get crazy over large datasets. You and I know that 50,000 may be
necessary because the user may wish to resort, refilter, etc, and my have
legitimate needs to have it all available, as opposed to fetching it
multiple times.

50,000 is doable if the pc's ram is sufficent and the table is not too wide
(ie, 20 - 25 cols). It will load, with a gig of ram, in seconds. I ensure
that all of my clients have 1 gig of ram - it's cheap and necessary.

I also try to load larger tables, sometimes 150,000 even more. It can take
a while to load and I offer filtering where possible, but when the user
needs it, they simply wait out the load.

HTH,

Bernie Yaeger

 

[Mary Chipman]

Okay, what precisely does "worst case" mean, then? that all 50,000
rows of data are fetched at some point during the user's lifetime?
Precisely how long that would take is going to depend on a lot of
external factors such as network speed, etc. You'll need to test it.

-- Mary
MCW Technologies
http://www.mcwtech.com