In developing a web-based application using ASP and .NET 2.0, how many records are too much?

Question

The application is for submission to a system where there is a master record (the submission) and secondary records. A second page allows the user to edit individual sub records in a grid, like an Excell sreadsheet in appearance. The main record has about 20 fields, perhaps 2 K of data and the sub records about 5 or 6 fields representing perhaps 150 characters. There are no graphics to speak of, all data is text.
Think of it like a class record with the main record having: subject, teacher, schedule, etc and then the sub-records would be the students with name, age, grade and mark.
As we add students, the performance starts to suffer. Why and what performance would you consider reasonable. Are we doing too much allowing the user to edit up to 50 students using a grid like this?
Back-end is Oracle, browser is IE and it runs over an enterprise WAN with the odd dial up user but most on 100MB ethernet.

Answer 1

Once your data is retrieved the page is virtually disconnected so unless you notice a major prob then you should be fine. However, depending on how you wrote your DAL/BLL layer you may be pulling back all the records every time you do an edit or any postback for that matter.

The only records each user should be getting is the ones they need, NOT the entire database. Unless you code it not to, that is exactly what its doing. So between pulling back all the records and multiplying that by each user you could really be waiting a while for each postback.

From a users perspective you might want to use a detailsview with your grid to make it easier to edit each record.