#! /usr/bin/perl -w

use strict;
use Plucene::Simple;
use Data::Dumper;

my %documents = (file1 => 'content1', file2 => 'content2');

    my $index = Plucene::Simple->open( "~/MyPerl/QA/data/index" );
    for my $id (keys %documents) {
        $index->add($id => $documents{$id});
    }
...