I think there's something you're not showing us. That error message looks to me as if you tried to interpolate a reference into your query string. For example:

my $stuff = [ 'things', 'items', 'etc.' ];
my $query = "SELECT $stuff FROM foo";
print $query, "\n";
__END__
SELECT ARRAY(0x504290) FROM foo
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Is this possible? It would probably be useful, from a debugging standpoint, to print out your query before you send it to the database.