Relationship handling and scaling


I am curious how others are handling selecting valid values from large

By way of example, I have a user table that tracks the mailing address
of the user. To gather the state code, I build a dropdown that has all
of the possible options, and it works fine. No response time issues or
anything. I suppose this type of dropdown list could probably scale to
perhaps as many as two or three hundred entries before it starts getting
unwieldy, both for the response time, as well as having the users deal
with such a large list.

In another case, the user needs to select one of some 15000 valid
entries. The user does not want to scroll through them all, but needs
to have some way to search over them and select one. In my old
mainframe days, the user could either directly type in the record key if
they knew it, or hit a function key to pop up a list, and then populate
the screen field with the selected record key from the popup.

What is the rails way of handling large select lists? Ideally, it
should work regardless of whether javascript is turned on.

Along the same line, I have a one-to-many relationship between two
tables. When editing the master record, I suppose the bottom part of
the form could show a set of rows containing the children. I’d like to
in-place edit the children rows. Is there a public example of how to
handle the view and controller actions in such a case? Or are there
better practices for dealing with the user interface aspects of a 1:m

Thank you for any advice you can offer.