A database table size issue

[sophate]

Dear Monks,

I have a huge database table which is over 30GB. I would like to create a Perl script that reads the table row by row. Process the data after reading each row.

I've written the script below but I run into a capacity issue right away as the script eats up all the memory when it tries to store the whole table into an array. Here are the codes.

#!/usr/bin/perl
use DBI;

$ENV{'FREETDSCONF'} = '/home/test/config/freetds.conf';
$ENV{'SYBASE'} = '/home/test/sql_server_15_0-64bit';

my $SERVER = 'TEST';
my $DB = 'test';
my $USER = 'admin';
my $PASSWD = 'admin';
        
$DB_Ref = DBI->connect("DBI:Sybase:server=$SERVER;database=$DB",
                        "$USER",
                        "$PASSWD",
                        {syb_err_handler => \&syb_err_h})
                or die "Couldn't connect to $DB : " . DBI->errstr;
$DB_Ref ->{RaiseError} = 1;
$DB_Ref ->{PrintError} = 1;
$DB_Ref ->do("set dateformat ymd");

## The table testTable is over 30GB
## The line below eats up all RAM on the server
my $testArray = $DB_Ref->selectall_arrayref('select * from testTable')
+;

## Do something on each row here

Can I output the results of the query one row at a time? Something like an input stream so that I can process the results row by row with something like "while <QUERY_STREAM> {}" to save memory? Many thanks.