On google group on Oracle server (http://groups.google.com/group/comp.databases.oracle.server) i’ve seen this:
“By accident, I found the solution for this problem on MetaLink :
Bug 4652274 – Explain Plan Differs With Different Users
It has to do with the init parameter secure_view_merging, which is new since
10gR2. Setting it to FALSE in the spfile and boucing the instance resolved
all my problems … Now queries on view from another schema have the same
exection plans when executed by the view owner compared to another user.
I’ve noticed this question because last person to write was Jonathan Lewis. The problem arised seems bad, Oracle in his note says that’s not a bug but an expected behaviour. Since my memory is not so good i’ve decided immediatly to write this here.
See comments for correct parameter name, thanks to David Jeffrey