I could store a hash in a db file with DB_File. It has been done since now I have a DB_file (*.db) in my hard disk which is about 4 GB, However, I can not re-access it. 
$DB_BTREE->{'flags'} = R_DUP ;
$x = tie %dictf, "DB_File", "f.db", O_RDWR|O_CREAT, 0666, $DB_BTREE
+ or die "Cannot open file f.db: $!\n";
 
my $number = keys %dictf;
print "$number\n";

my $number = keys %dictf;
print "$number\n";

$key = $value = 0 ;
for ($status = $x->seq($key, $value, R_FIRST) ;
$status == 0 ;
$status = $x->seq($key, $value, R_NEXT) )
{ print "$key -> $value\n"; }

[download]
and the result is: 
0

[download]
while I have: 
> ls -lh *.db
-rw-r--r-- 1 xxxxx xxx 4.2G Dec  3 14:03 f.db

[download]
as my database. What is wrong in my code?

In reply to re-tie the previous db by Anonymous Monk

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