"Fly.Li" <fly2nn(at)126(dot)com> writes:
> version: PG8.2.2
> MY Question:
> Why must "take the same number of parameters" ?
Because the GIN code will call it with a particular number of arguments.
> When I use tsearch2, I found that gin_extract_tsquery() has 3 parameters, it
> break the rule "take the same number of parameters".
3 is the correct number of parameters for an extractQuery function
(before 8.4 anyway), so I'm not clear what you are complaining about.
regards, tom lane