Most Oracle reads are pseudo-random. They are not truly random, just pseudo-random, because some segments are accessed more heavily than others, and within segments some data is normally accessed more heavily than the rest. For example, in a sales database the orders table would be accessed more heavily than the cancellations table, and more recent orders and more popular products would be accessed more frequently than others would. The parts of the datafiles that are accessed most heavily are called hot spots.
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