i have 20 databases, for example, and each database has 20,000 records in them.

the goal of the software is to let the user choose what data they want from those databases (the source) and have it moved into a single database (the destination).

i'm trying to think of the best way to display the databases so the user can choose which ones they want to pull from, then display the huge amounts of records they want to send from each database (sometimes they want to send all).

right now i'm thinking this...

a list of databases that they can multiselect. as they select each database the records from that database are displayed in an even larger list...a list they can filter. from there they can select those records and have them queued up to be moved to the destination database.

problem right now is that the queue list can get really long, especially if they want all records (20,000) from one source database. i'm sure i'll figure that out with some time, but i wanted to see if you all had any other suggestions on the best way to do this.