As far as I know Netezza for string searching only offers two functions le_dst(str_expr_1, str_expr_2) and dle_dst (str_expr_1, str_expr_2) as mentioned here
Are there any other more advanced options for fuzzy searching in netezza like oracle has Oracle Text for example
Apart from Those two fuzzy matching functions, there are a couple of phonetic matching functions as well. See these:
I hope that helps in your case :)