my $myQuery = $dbh->prepare( "SELECT source FROM myTable" );  

$source =~ s/<element xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\" xmlns:xsd=\"http:\/\/www.w3.org\/2001\/XMLSchema\"><items><item><data>//g;

$source =~ s/<\/data><\/item><\/items><\/element>//g;