PS: please don't harass me for not using strict. I promise I am going to use strict once I figure this out.

You have something very important fundamentally backwards.

strict does not exist to harass you but to help you figure it out!

Update: I second the recommendation from neilwatson. One of the many advantages of using Test::More is how simple your syntax can be:

#!/usr/bin/perl
use strict; use warnings;
use Test::More tests => 1;

my ( $DS1, $DS2 ) = get_hashes();
is_deeply( $DS1, $DS2 );


sub get_hashes {
    my %DS1 = (
        PERL => [
            {
                TABLES => {
                    TABSCHEMA => "VARCHAR(128)",
                    TABNAME => "VARCHAR(128)",
                }
            },
            {
                COLUMNS => {
                    TABSCHEMA  => "VARCHAR(128)",
                    TABNAME    => "VARCHAR(128)",
                    COLNAME    => "VARCHAR(128)",
                    PARTKEYSEQ => "SMALLINT",
                }
            }
        ]
    );

    my %DS2 = (
        PERL => [
            {
                TABLES => {
                    TABSCHEMA => "VARCHAR(256)",
                    TABNAME   => "VARCHAR(128)",
                }
            },
            {
                COLUMNS => {
                    TABSCHEMA  => "VARCHAR(256)",
                    TABNAME    => "VARCHAR(128)",
                    COLNAME    => "VARCHAR(128)",
                    PARTKEYSEQ => "SMALLINT",
                }
            }
        ]
    );

    return ( \%DS1, \%DS2 );
}

__END__
[download]

Output:

1..1
not ok 1
#   Failed test at 1157115.pl line 7.
#     Structures begin differing at:
#          $got->{PERL}[0]{TABLES}{TABSCHEMA} = 'VARCHAR(128)'
#     $expected->{PERL}[0]{TABLES}{TABSCHEMA} = 'VARCHAR(256)'
# Looks like you failed 1 test of 1.
[download]

Note, though, that this will only show the differences one at a time, so if you are looking for a comprehensive diff, this is not the way.

Hope this helps!