The first thing that has to be done is come up with the desired operators. Note that five operators are needed. There is one operator for each strategy. A strategy of an index is really like a plugin that allows you to put in your own code.
Before getting started, I have compiled some test data:
CREATE TABLE t_sva (sva text); INSERT INTO t_sva VALUES ('1118090878'); INSERT INTO t_sva VALUES ('2345010477');
Now that the test data is there, it is time to create an operator. For this purpose, PostgreSQL offers the CREATE OPERATOR command:
test=# \h CREATE OPERATOR Command: CREATE OPERATOR Description: define a new operator Syntax: CREATE OPERATOR name ( PROCEDURE = function_name [, LEFTARG = left_type ] [, RIGHTARG ...