Rewrite, normal execution vs. EXPLAIN ANALYZE

Hi,
From the code I understood that when executing a query "normally", in 
READ COMMITTED mode, we take a new snapshot for every query that comes 
out of rewrite.  But in an EXPLAIN ANALYZE, we only update the CID of 
the snapshot taken when the EXPLAIN started.

Did I misunderstand the code?  And if I didn't, why do we do this 
differently?


Regards,
Marko Tiikkaja