Jun

26

Apple “Genius”

Filed Under Mac | 6 Comments

Recently I sold my old, damaged MacBook Pro on eBay, and in doing so I claimed that there was a chance that it could be repaired (by Apple) for free. But how, you may be wondering, could I make such a bold claim? Was it all a strategy to over-sell my broken laptop? Not in the least. Back when I first found out about this Apple’s KB article, the contents of which appeared as though they would entitle me to a free repair, I headed straight to the Apple Store at the Fairview Mall in Toronto. I’d had a fairly positive customer care experience there just a week before, and I was rather optimistic that they’d repair it for me.

After I arrived at the Genius bar, I had to wait for quite a while before having the displeasure of dealing with an uncooperative “genius”, a young guy whose unfriendly attitude far outweighed any technical know-how he may have had. He immediately denied any knowledge of video issues on MacBook Pros from 2007 and only agreed to check my laptop after I’d showed him a printout of the knowledge base issue mentioned above. He essentially humored me in a rather reluctant way, and after a very short while told me that my laptop didn’t qualify for the free repair. Annoyed by this guy’s lack of care regarding my problem, I left the store.

Around the time when this situation arose, I had already visited the Genius Bar several times regarding various matters and was feeling a bit tired of dealing with a broken laptop. Ultimately I gave up on my old MacBook Pro (my first Mac ever) and when it was economically possible, I purchased a replacement laptop. Though my old MacBook Pro had cost me time and money, I felt that its tale was done and over with once I brought my new laptop home. That is until the day I decided that someone else could get more use out it than I was (as it was just sitting unused in my office), and that I could get a few bucks by selling it on Ebay. The old Mac’s auction wrapped up with a selling price of $578. It was bought by a fellow from Ontario, who was a very pleasant person to deal with.

If fact he was so kind that he sent me a follow-up regarding his own attempt to get the laptop fixed. Here’s what he wrote:

Just a quick update. The testing on the Macbook Pro was conducted this week, and found to conform to the warranty exception Apple identifies with the nVidia chip problem. A replacement is being installed now, but likely won’t be ready until next week. While you’re probably more content to wash your hands of the whole matter, I’d seriously consider a complaint against the apple store you took it to, and more specifically against the “genius” who served you, given he was clearly no genius at all, and likely cost you significantly in time and money as a result. Hope you’re having a good day.

I am genuinely happy for the guy. He took a risk by buying a broken laptop from me, trusted my story to be true (as it was!), and ended up scoring a working laptop that’s (now) worth far more than what he paid for it. His bet paid off and I wish him all the best.

The truth of the matter is that, as he says, I’m glad to “wash my hands of the whole matter”. At this point there is little Apple would do, even if I made a fuss about it (which I’m not going to, of course). Next time I walk by that particular Apple store, I may have a word with the manager (regarding the Genius I’d dealt with), but that’s about it.

The moral of the story is not that Apple’s customer care sucks or rocks. Apple Genii are just people, some are very good, others exceptionally bad, and most of them are somewhere in between. The take-home lesson for me here was that when dealing with Apple, if you get turned down by one store, you shouldn’t stop there! Take the time to visit a couple more and to persue the matter as far as you can.

Jun

16

Selling my old MacBook Pro

Filed Under Mac | 1 Comment

A few days ago I placed my old MacBook Pro up for auction on Ebay, with a starting price of $200 and no reserve. While the auction has generated interest, so far there has been only one bidder. The auction ends in a little over two days. If you are interested, please read the description carefully and then bid with confidence. Despite being damaged, a laptop like this is still worth a few hundreds dollars due the sheer amount of working parts in it (CPU, memory, hard-drive, LCD matte screen, new battery, MagSafe adapter, remote control which works with new models too, etc…). It could be used as an extra Mac in your arsenal if utilized through Remote Desktop or repaired. There is also a chance that it could be repaired for free by Apple (though of course I cannot guarantee this point).

Ebay Listing

Jun

5

Do Androids Count Electric Sheep with DB2 or MySQL?

Filed Under DB2, Mac, Ruby, Ruby on Rails | 26 Comments

Counting rows is an ubiquitous operation on the web, so much so that it’s often overused. Regardless of misuse, there is no denying that the performance of counting operations has an impact on most applications. In this post I’ll discuss my findings about the performance of DB2 9.5 and MySQL 5.1 regarding counting records.

For those of you who are not into science fiction, let me clarify that the odd title of this post is a tongue-in-cheek reference to the great novel, Do Androids Dream of Electric Sheep?.

I connected to the database, created the table, imported the data and benchmarked counting operations using ActiveRecord in a standalone script. Here is the code I used:

#!/usr/bin/env ruby
require "rubygems"
require "active_record"
require 'benchmark'

ActiveRecord::Base.establish_connection(
  :adapter  => :mysql,
  :username => "myuser",
  :password => "mypass",
  :database => "mydb")

ActiveRecord::Schema.define do
  create_table :people, :force => true do |t|
    t.string :name, :null => false
    t.string :fbid, :null => false
    t.string :gender
    t.string :profession
  end
end

class Person < ActiveRecord::Base
end

# This can be sped up by performing an import instead
Person.transaction do
  File.open("person.tsv").each_line do |line|
    line = line.split(/\t/)
    p = Person.new
    p.name = line[0]
    p.fbid = line[1]
    p.gender = line[6]
    p.profession = line[17]
    p.save!
  end
end

n = 100
Benchmark.bm(26) do |x|
  x.report("Count all:") { n.times { Person.count } }
  x.report("Count profession:") { n.times { Person.count(:profession) } }

  x.report("Count females:") do
    n.times { Person.count(:conditions => "gender = 'Female'") }
  end

  x.report("Count males w/ profession:") do
    n.times { Person.count(:profession, :conditions => "gender = 'Male'") }
  end
end

Please note that importing records in a huge transaction containing hundreds of thousands of INSERT operations is far from the most efficient way to import. Massive imports of data using the load/import facilities provided by each database is the way to go (also see the ar-extensions plugin). The lengthy import wasn’t benchmarked here though, so it isn’t determinant for this article.

people.tsv is a 92.7 MB tab separated values file that contains 875,857 records from the Freebase project (in my file I removed the header line, leaving only records).

For those who are not familiar with ActiveRecord, the queries executed behind the scenes are (in order):

SELECT count(*) AS count_all FROM people

SELECT count(people.profession) AS count_profession FROM people

SELECT count(*) AS count_all FROM people WHERE (gender = 'Female')

SELECT count(people.profession) AS count_profession FROM people WHERE (gender = 'Male')

While the table definition (for MySQL) is:

CREATE TABLE `people` (
	`id` int(11) DEFAULT NULL auto_increment PRIMARY KEY,
	`name` varchar(255) NOT NULL,
	`fbid` varchar(255) NOT NULL,
	`gender` varchar(255),
	`profession` varchar(255)
) ENGINE=InnoDB

As easily verified by enabling logging with:

ActiveRecord::Base.logger = Logger.new(STDOUT)

Without much further ado, here are the times I obtained on my last generation MacBook Pro 2.66 GHz with 4 GB DDR3 RAM, and 320 GB @ 7200 rpm hard disk, running Mac OS X Leopard:

MySQL:

  Count all:                  42.467522
  Count profession:           52.130935
  Count females:              54.575469
  Count males w/ profession:  64.046631

DB2:

  Count all:                  5.818485
  Count profession:           7.714391
  Count females:              8.556377
  Count males w/ profession:  9.656739

Or in graph form:

COUNT performance graph

That’s an impressive difference. To be exact, in this example DB2 was between 6 and 7 times faster than MySQL. In the case of COUNT(*), DB2 counted almost a million records in 58 milliseconds, or in about the blink of an eye according to Wolfram Alpha.

For those who are skeptical, please note that DB2 was not manually fine-tuned in any way. The client codepage was set to 1252 to allow Greek letters, and the log size was increased to permit such a huge transaction during the import. That’s it, no optimizations were attempted. This is DB2 Express-C out of the box. It looks like smart androids count electric sheep with DB2 after all. :-P

The advantages of DB2 over MySQL when dealing with a massive volume of traffic are well known (and not limited to performance either), but DB2 can dramatically improve performance even for your average web application. And DB2 9.7, which will be released this month, increases the performance and the ability to self-tune itself to the available resources and required workload even further. If you’d like to try DB2 Express-C for yourself, you can download it here. It doesn’t cost you a dime to obtain and can be used for development, testing and production absolutely free of charge.

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