Although I have been using perl for a number of years now I haven't used any database packages. After reading about persistent data in "Mastering Perl" I decide to use DBM::Deep and compare it with Storable. In the following code my hash has about 350 elements each being a reference to an anonymous array of 13 values (file stats, extension, etc). I would estimate that there is 150-200 bytes of data per hash element. I sort the hash (to make the $db->import faster) and then time both a save by DBM::Deep and by Storable.

my $db=DBM::Deep->new(file=>"c:/testpad/collector.Deep",autoflush=>0);
my %hash_sorted=sort %hash;
my $st=time;
$db->import(\%hash_sorted);
my $et=time;
my $deltatime=$et-$st;
say "Time required to write hash using DBM-Deep: $deltatime secs";
$st=time;
store(\%hash_sorted,"c:/testpad/collector.storable");
$et=time;
$deltatime=$et-$st;
say "Time required to write hash using Storable: $deltatime secs";

[download]


The result is as follows:

Storable: under a second elapse time and a file size of 36.9K
DBM::Deep: 15 secs and a file size of 4.0 megs

The overhead in cpu and file size with DBM::Deep seems excessive to me. Any comments? Is this what to expect from DBM::Deep or any other DB package? Are there options I have missed?

I would appreciate any insight you can provide.

In reply to DBM::Deep overhead by perlpipe

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