how to retain data in Delta after extraction

Hi Experts,

We are suppose to extract delta from same datasource for multiple cubes ... from the source system only ... now after we extract delta for cube A, there is another cube B which is suppose to extract delta from the same datasource at different times, is there any setting that we need to do to retain delta after extraction of first delta... so I can use it for another cube ...

thanks.

Sunil.