Okay, don't kill me for suggesting something that isn't really a database, but if you do not have access to somthing like Oracle or MySQL, a few simple lines of perl code can get you up and running if you use Data::Dumper. What my example does is print a copy of the %db hash structure to a file that you can later read in using a do() statement. Here is some sample code:

#!/usr/bin/perl
use Data::Dumper; #Use the Data::Dumper module
use Fcntl ':flock'; #Need the flock module also

&dbfile("open", "database"); #open database for reading & writing

#You can do any data struture you want with hash %db
$db{'hash'} = "hash_value";
push @{$db{'array'}}, "array_value";

&dbfile("close", "database"); #save and close database

#If this is a CGI script, uncomment the following line:
#print "Content-type: text/html\n\n";

&dbfile("open", "database");
print "Hey look at the value in \$db{'hash'}: $db{'hash'} \n";
print "And what's in \$db{'array'}[0]?: $db{'array'}[0]\n";
&dbfile("close", "database");

#Sub - opens/closes databases
sub dbfile {
if ($_[0] eq "open") { #open a database
open LOCKFILE, ">>lock.lck" or die "Error! Could not lock database!";
flock LOCKFILE, LOCK_EX or die "Error! Could not lock database!";
do "$_[1].dat";
}

if ($_[0] eq "close") { #save & close database
$Data::Dumper::Purity = 1;
$Data::Dumper::Indent = 0;
open FILE, ">$_[1].dat";
print FILE Data::Dumper->Dump([\%db], ['*db']);
close FILE;
close LOCKFILE;
%db = ();
}

#mmm... not opening database or closing.
#What are you trying to do?!
if ($_[0] ne "open" && $_[0] ne "close") { die "Error! Wrong parameter
+ passed to db_file()!"; }
}
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It is missing some stuff such as strict, making sure you don't open 2 databases, try to close a database that does not exist, or even making sure that you save to the same database that you opened (though this is not really a bug; it would allow you to copy a database), etc. But it gives you a general idea, so I figure it is a good enough of an example.

Also, here is the contents of file "database.dat" from my example. You'll notice I have taken out indentation to get rid of the extra space needed for all the spacing.:

%db = ('array' => ['array_value'],'hash' => 'hash_value');
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