Programming on Bhaak's Blog

Accessing ActiveRecord attribute slower than local variable

Thu, 14 May 2026 15:23:13 +0200

I was deep in a performance optimization flow when I stumbled upon this part in a ruby-prof graph:

- 17.59% (73.45%) SomeTable::GeneratedAttributeMethods#some_attribute [30263106 calls, 44665545 total]
  - 15.24% (86.62%) ActiveRecord::AttributeMethods::Read#_read_attribute [30263106 calls, 49437307 total]
    - 11.82% (77.58%) ActiveModel::AttributeSet#fetch_value [30263106 calls, 49068748 total]
      - 5.44% (46.06%) ActiveModel::AttributeSet#[] [30263106 calls, 49303667 total]
        - 2.32% (42.58%) Hash#[] [30263106 calls, 72892138 total]
      - 2.05% (17.36%) ActiveModel::Attribute#value [30263106 calls, 49274896 total]

ActiveRecord stores attributes internally in a hash, which is more expensive than I expected.

Avoid Integer for File Sizes in Postgres

Thu, 05 Mar 2026 12:43:14 +0100

Here’s a small bug we recently encountered in production. Occasionally, PDF generation jobs would fail, and the cause turned out to be a small oversight when designing database tables.

The PDF metadata is stored in a table, and the column for file size was defined as integer, also known as int4.

Since this data type is signed in Postgres, those 4 bytes only allow for files up to 2.1 GB (2 147 483 647 bytes). You might think, 2^31 bytes ought to be enough for everybody … except apparently for our PDFs.

Code Golfing Leap Years in Ruby

Tue, 20 Jan 2026 13:25:01 +0100

A work buddy challenged me to a bit of Ruby code golfing.

Write a program to print all leap years from 1800 up to and including 2400.

The website he got the challenge from (https://code.golf/leap-years#ruby) has a neat feature: it can run your code and verify whether the output matches the expected result.

I’m usually not much of a code golfer, I generally prefer writing code that’s performant and readable rather than short and cryptic, but this turned out to be a fun little challenge and even somewhat educational.

Simulating candle flickering with a simple RNG

Thu, 23 Nov 2023 12:48:00 +0100

While preparing to attach the electrical candles to the Christmas tree, a question popped into my mind.

There are electrical candles that simulate the flickering of real candles. How complex would an algorithm have to be to be convincing?

I wrote a quick proof of concept in Ruby for a script running in the terminal which just randomly chooses a grey value to display.