I guess we're all reading these a little too fast. And I think I confused you with my comment about OO and use base. You don't need that for what you're doing, though you do need it for Exporter which we overlooked before.

Here's an annotated version of something that should work. I've reordered/simplified lines for clarity. For example, you don't really need the BEGIN block and assuming you're using Perl 5.6 or later, you can replace all the use vars with our. 

# MyMod.pm
use strict;
use warnings;
package MyMod;

use constant MYMOD_DEFAULT => 1; 

use base qw( Exporter );           # You need to subclass Exporter
our @EXPORT = qw( MYMOD_DEFAULT ); # No extra parens needed

1;

[download]
# MyMod/db.pm
use strict;
use warnings;
package MyMod::db;

use MyMod; # imports MYMOD_DEFAULT automatically

sub fred {
        print "hello" if (MYMOD_DEFAULT);
}

1;

[download]
# fred.pl
use strict;
use warnings;

use MyMod::db;

MyMod::db::fred(); # fully qualified call

[download]

Output of fred.pl:

hello

[download]

-xdg

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In reply to Re^3: Can't import constants in multiple namespaces by xdg
in thread Can't import constants in multiple namespaces by mje

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