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List, This is a general question for my own education. Something I
read earlier today triggered some ideas in my head, and out of curiosity I’m
researching and learning. What characteristics of data sets lend themselves to
reasonable user-defined data types? Are there characteristics of a data type
that would limit it’s usefulness? I’ve reviewed the PostgreSQL documentation on user
defined data types. It seems that data types that can’t be ordered or
compared for equality would be bad candidates. After all, if a data type can’t
be indexed or used in a where clause, what value does a custom type bring over
a binary or textual representation? Additionally, the careful tone in the documentation
regarding the definition of the comparison and equality operators suggests that
these definitions may be an exceptionally delicate matter. Any experience or
suggestions on the matter? Tim Hart |
