what's a "reasonable" length of time to keep a cursor open?

I've got a long running job that is using the database to queue up entries to be processed.

Sometimes a couple of million items might be dumped in the queue, needing a couple of days to process.

Of course, keeping a cursor open for several days is not a good idea and will probably get an oracle error when the redo log or somesuch is expired.

So, I periodically close my active select cursor and reissue the query.

What's a "reasonable" length of time to keep a cursor open? I'm not looking for a hard and fast number, just a general concensus. Is one hour for keeping a cursor open raising eyebrows? one minute?

Many TIA!
Mark

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Mark Harrison
Pixar Animation Studios