This function looks for a pattern and returns the first position of the pattern. Optionally, you can indicate
the start_position you want to begin the search. The occurrence parameter defaults to 1 unless you indicate that you are looking for
a subsequent occurrence. The default value of the return_option is 0, which returns the starting position of the pattern; a value
of 1 returns the starting position of the next character following the match. This function returns the starting position of a
pattern, so it works much like the familiar INSTR function. The main difference between the two functions is that REGEXP_INSTR
lets you specify a pattern instead of a specific search string; thus providing greater versatility.