File Organization
Cost Model
- Page Accesses: How many pages are read or
written by an operation? Ignoring CPU costs.
- Some page accesses are cheaper than others.
- Random Accesses: 5−15 msec for a
hard disk. 0.1 msec for an SSD.
- Sequential Accesses: Much cheaper than
random access, on average, assuming that a random access gets
more than one page.
- Discussion will assume unique keys.
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