Hi,
Documents are only loaded into the active segment, in your case 2011.
Meaning, that you will have the following case:
Segment 1 2007
Segment 2 2008
Segment 3 2009
Segment 4 2010
Segment 5 2007 + 2011
I use normally the Segment ID with the archiving date and not the business date.
And for the expiration, I prefer to use Expiration by Load and not by Segment.
Concerning the performance of selecting on several tables...
well for the moment it was never a big issue, at least for the moment.
Well what you could do (but that is not nice...) would be, close 2011, do your load correction on the new table, close the new table, and the load of 2011 will go in a new table:
Segment 1 2007 (1st Part)
Segment 2 2008
Segment 3 2009
Segment 4 2010
Segment 5 2011 (1st Part)
Segment 6 2007 (2nd Part)
Segment 7 2011 (2nd Part)
Not nice, but better from a performance point of view!
I hope somebody will have some better idea than me in that regard!
Cheers,
Alessandro