Creating a new operator
Now, let's take look at how we can add a new operator in PostgreSQL. Adding new operators is not too different from adding new functions. In fact, an operator is syntactically just a different way to use an existing function. For example, the + operator calls a built-in function called numeric_add and passes it the two arguments.
When you define a new operator, you must define the data types that the operator expects as arguments and define which function is to be called.
Let's take a look at how to define a simple operator. You have to use the CREATE OPERATOR command to create an operator.
In Chapter 2, Server Programming Environments, we wrote a function to calculate the Fibonacci number of a given integer. Let's use that ...
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