But I see your point about creating such a module myself and uploading it to CPAN. And ~10 years ago it was the approach which I probably have choose, because all other libraries are here on CPAN.

Perl have lost critical mass of its users, who will fill the gaps on missing modules, unfortunately for me and for other perl users.

"who will fill the gaps on missing modules"

Various 'Datatables' modules exist on cpan, you didn't say which ones you tried and how they failed. Luckily, you don't need a perl module to return the data required for datatables, as has been made clear to you, the perl core modules achieve this without issue.

this is what I've tried

use strict;
use DBI;
use DataTables;

my $dbfile = 'base.db';
my $dbh = DBI->connect("dbi:SQLite:dbname=$dbfile","","");
my $dt = DataTables->new(dbh => $dbh);

#set table to select from
$dt->tables(["t"]);
 
#set columns to select in same order as order of columns on page
$dt->columns(["LPAR", "UCODE", "BOX", "Serial Number", "Box Name", "TE
+ST", "N_OF_TEST", "N_OF_ERR"]);
 
use Mojolicious::Lite;

#print json back to browser

get '/data-source' => sub {
    my $c = shift;
    $dt->print_json;
};
app->start;
[download]

Ok, now I've remembered on what's missing here.
I need to work with database of 10_000_000+ records, those do not fit just JSON.

I see that this module recently updated... How can I trust version 0.08? Author makes it clear that the module far from robust?