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20000 List Items

I have 20000 Items (LastName, FirstName) I need to display in a DropDown
box, but it takes a while to load them after every postback.
What would be the best way to allow user to view these 20000 items without
loading all of them every time?
Thanks

Peter
Jan 27 '06 #1
3 1165
On Thu, 26 Jan 2006 20:50:53 -0600, Peter wrote:
I have 20000 Items (LastName, FirstName) I need to display in a DropDown
box, but it takes a while to load them after every postback.
What would be the best way to allow user to view these 20000 items without
loading all of them every time?


You might want to consider a paged display approach. Only show 25, 50, or
100 items at a time, with forward and back buttons.

Or, you might want to consider a "filtered" search approach where the user
clicks on the first letter of the group they want to list, or provide a
textbox for them to type a few letters to search on.

Or, you could use an AJAX approach to filter results dynamically in real
time, similar to Google Suggest, though that's certainly far more advanced.

http://www.google.com/webhp?hl=en&tab=iw&complete=1&q=
Jan 27 '06 #2
> I have 20000 Items (LastName, FirstName) I need to display in a
DropDown
box, but it takes a while to load them after every postback.


Even populating a combo box in a winform app takes a while with 20000 items.
I would question your "Need" to put them all in this list. Most people are
only willing to scroll through a relatively small list. I am unable to recall
the guidance sizes I've recently read, but believe you should keep it below
50 and more preferably around 10 as those are levels which a user is willing
to scroll through.

Jim Wooley
Jan 27 '06 #3
The way we resolved similar issue in the past was as follows:

We identified the most commonly used items (in your case names) based
on its reference/usage, we realized that the usage count was as follows

Item Reference Count(*)
====================
Item-25 200
Item-2 186
Item-3 177
Item-99 144
Item-100 101
<In our system only 5 items fell in above categogy>
Item-1 99
Item-6 96
Item-5 94
.........
<In our system aboutn 12000+ items fell in this categogy>

We then displayed only those item in the drop-down whose refrence count
was > 100 and that filtered the list to a smaller count, that was user
could select conolodated lsit only on an need basis, else they would
see only 5 items

Hope this helps
Jim Wooley wrote:
I have 20000 Items (LastName, FirstName) I need to display in a
DropDown
box, but it takes a while to load them after every postback.


Even populating a combo box in a winform app takes a while with 20000 items.
I would question your "Need" to put them all in this list. Most people are
only willing to scroll through a relatively small list. I am unable to recall
the guidance sizes I've recently read, but believe you should keep it below
50 and more preferably around 10 as those are levels which a user is willing
to scroll through.

Jim Wooley


Jan 29 '06 #4

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