One funny and yet powerful idea related to one-to-one relations came to my mind recently. Imagine a simple one-to-one relation whenever a second object always exists. …

Optimizing Redis memory usage for strings, integers, jsons and anything you like — Whats inside: How much +1 symbol to every redis key costs, and does key names optimization worth it? Key/value store abstraction over redis hashes. Getting 10 times less memory for stored integers or getting 5% memory discount for medium previews. To GZip or not to gzip — comparision of gzipping…

English version: Simple sample for Postgres and ruby. Что интересного в статье: Пример быстрого псевдослучайного семплинга массивов в постгресе и руби. Сравнение различных реализаций сэмплирования массивов в постгресе и руби, с предложенным: Для постгреса на массивах в 1000 элементов в 6.5 раз быстрее комбинации order by random() ( в 15…

Русская версия статьи: Simple sample в ruby и Postgres’е. (рус) Whats inside: An example of a fast pseudo-random sampling of an array in ruby and Postgres. Comparison between different sampling implementations with a given one. In short for Postgres it’s much faster then order by random() or where random < 0.xx. …

English version: From Action To Any Подкапотные нюансы AnyCable для мигрирующих с ActionCable. Что будет интересного: Как можно посчитать количество пользователей онлайн в ActionCable и почему это сломается в AnyCable Чем отличается current_user в базовом классе Connection при использовании AnyCable от ActionCable. Почему AnyCable гарантировано ломает devise при использовании Rails…

Русская версия: От Action к Any Internal aspects you may notice while migrating from ActionCable to AnyCable What’s inside: How to count online users in ActionCable and why it would break in AnyCable Small differences between current_users defined by identified_by in Connection::Base class. Why AnyCable will break your devise authentication…

Postgres derailed indexes. Part 2 — How to miss a GIN index in your queries you can read in Yo-ho and the bottle of GIN. This one is example how to miss a b-tree index using varchar_pattern_ops/text_pattern_ops in non-C locale environment. Autocomplete case The best reallife case scenario would be an autocomplete implementation. Assume you need a fast…

There seems to be something wrong with our bloody index today! — I will not give a speach about indexes in general or indexes special features in the PostgreSQL. Lets assume you know what indexes are, what is their value in delivering right amount of a needed data within a suitable amount of time. …

A reasonable way of Code-Test-Document triad organization in a ruby based application with a conceptions and tools overview and comparision, containing some code examples. Back then When I was doing my first steps as C++ Win32 programmer, I was surprised how much Microsoft valued it’s documentation. A MSDN documentation package was a…