Error refreshing and refresh deleted records

I have an Oracle ADOquery and a clientdataset for manipulate the data.
1. If i close the adoquery and open it at runtime, then the
clientdataset.refreshrecord doesnt work.
2. ?Anybody knows how can i accelerate the refreshrecord?
3. When i select some records in my query and other user deletes one of it
when i position on it and try to refreshrecord with the cientdataset i
receive an error ?how can i control this removing the record from the
selection in the dataset?

Thanks.