Performance of the affected query would be as good or as bad as the performance is in the Oracle database.
Ask you Oracle DBA to do two things for you:
1) Get an explain plan for your query, you are gonna find Oracle explain plan pretty easy to follow.
2) Trace your query, tkprof the resulting trace file and help you in identifying wait events.
Those are the two tools you need to finetune affected query.
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Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.