A client has some applications developed in. NET running on an Oracle database version 10.1, and want to know the impact is to make the upgrade to version 10.2 and / or 11g. The idea is to get a guideline of things that will not work, or will have to be revised / modified, etc.
Now, if the jump is from 10.1 to 11g, there may be an issue because older versions of Oracle worked for Rules (and still holding potential for 10), newer versions now working for Costs (11g only works for costs .) So depending on how the current basis are 10.1 (Rules or costs), the upgrade may be more transparent, or review the queries require that the costs you can change rules by having a big performance problem.