Database & Oracle Reports 10g - passing large param lists

This may be more of an application architecture or design question, and it's certainly an Reports 10g question; I'll just toss it out and you be the judge :)

The environment: J2EE application, session management, etc. 10g back-end. User can pull up a list with potentially thousands or tens of thousands of records, paginated of course. They can arbitrarily flag or unflag records on this list at will, either one at a time with checkboxes, or by applying a variety of filters. The list of "flagged" records is maintained at the session level in the middle tier. The user clicks a button and Reports 10g is invoked to generate a mongo PDF for only those records which are flagged. The flags needn't be stored in the back-end, there is no need to persist them. At least, that's the idea.

The problem: at the session level, user might end up flagging tens of thousands of records. How can I pass this to Reports so that it knows which records to include in its report? It can't be a URL parameter, of course. One solution is to have the middle tier dump a list of these flagged records into the database (a temp table, perhaps), where Reports 10g can get at 'em. Unfortunately then I'm incurring some overhead on the back-end *and* I'm faced with potentially millions of records of DML per day just for using the database as a temporary scratchpad.

Is there a way to stream or send a large result set from J2EE to Reports 10g directly without using the RDBMS as an intermediary? Minimally we're talking about tens of thousands IDs, each potentially 15 characters long.

Bob

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