I tried the four variants on my Linux box (uncomment the one you want): 
#!/usr/bin/perl
use strict;
use warnings;

my @objs;
for my $i (1 .. 1_000_000) {
    # push @objs, { id => $i, name => "Object of class", number => int
+ rand 10 };
    # push @objs, bless { id => $i, name => "Object of class", number 
+=> int rand 10 }, 'My::Class';
    # push @objs, [$i, 'Object of class', int rand 10];
    push @objs, bless [$i, 'Object of class', int rand 10], 'My::Class
+';
}
print `ps -v | grep ^$$`;

[download]

It seems bless doesn't really change anything, but a hash versus array does. 

23235 pts/0    S+     0:00      0  2020 371111 359628  1.1 /usr/bin/pe
+rl ./1.pl
23225 pts/0    S+     0:00      0  2020 261035 249668  0.7 /usr/bin/pe
+rl ./1.pl

[download]

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re: Memory overhead of blessed hashes by choroba
in thread Memory overhead of blessed hashes by LanX

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