The idea is to request as much data as possible from the same tape file or to reduce the number of tapes involved. - The number of tapes a MARS request is going to access will have an impact on its scheduling on the server.
- A large number of tapes implies more waiting time.
- As a rule of thumb, two or more separate requests accessing files on different tapes are scheduled more efficiently than a single request accessing two or more tapes.
Additionally users should be aware of the following: - The data volume to be retrieved should be sensible, up to 20GB per request.
Check that your computer resources and limits are adequate for the amount of data to retrieve. - The number of fields to be retrieved should be also a sensible number, up to 600.000 fields per request.
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