Why not use both :) A simple demo for you

#!/usr/bin/perl
use strict;
use warnings;
use DBD::CSV;

# create db handle
my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_ext      => ".csv/r", RaiseError => 1,
}) or die "Cannot connect: $DBI::errstr";

# create csv table if not exists
my $table = 'mycache';
unless (-e $table.'.csv'){
  $dbh->do ("CREATE TABLE $table (
   uid    char(100), 
   line1  char(100),   
   line2  char(100),   
   line3  char(100),
   datetime  char(20)   ) ");
}

while (1) {
  # show records
  my $ar = $dbh->selectall_arrayref("SELECT uid FROM $table ORDER BY u
+id");
  print "$table.csv contains\n";
  print "  $_->[0]\n" for @$ar;
  print "\n";

  # input new or existing record
  print "Input unique id (q to quit,c to clear) > ";
  chomp( my $input = <STDIN> );
  exit if lc $input eq 'q';

  # clear
  if (lc $input eq 'c'){
    $dbh->do("DELETE FROM $table");
    next;
  }

  # check existing or new
  my @f = $dbh->selectrow_array("
    SELECT * FROM $table 
    WHERE uid = ?",undef,$input);
  if (@f){
    print "--\n $input EXISTS : @f \n--\n";  
  } else {
    my @f = ($input,'init1','init2','init3',scalar localtime);
    print "--\n $input NEW RECORD : @f \n--\n";
    $dbh->do("INSERT INTO $table VALUES (?,?,?,?,?)",undef,@f);
  }
}
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