"io.sys" <io(dot)sys(at)post(dot)cz> writes:
> I just tried to use function parameters $_[1], $_[2], $_[3] instead fixed strings.
> However, it is rejected by postgre as syntax error.
That's not a Postgres problem, it's a Perl problem. I'm no Perl
expert, but I think if you study the Perl docs carefully you will
find there are restrictions on what sorts of variable references
can be interpolated into a regexp ... and a subscripted reference
probably doesn't qualify.
regards, tom lane