integers. In practice the default operator class for the field's

datatype is usually sufficient. The main point of having operator classes

is that for some datatypes, there could be more than one meaningful

ordering. For an index on such a datatype, we could select which

ordering we wanted by selecting the proper operator class. There

are also some operator classes with special purposes:

ordering. For example, we might want to sort a complex-number datatype

either by absolute value or by real part. We could do this by defining

two operator classes for the datatype and then selecting the proper

class when making an index. There are also some operator classes with

special purposes:

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