44 Articles tagged “Yesql”

The reason why I like Unicode a lot is because it allows me to code in text based environments and still have nice output. Today, we’re going to play with Regional Indicator Symbol, which is implemented as a Unicode combinaison of letters from 🇦 to 🇿. For instance, if you display 🇫 then 🇷 concatenated together, you get 🇫🇷. Let’s try that from our PostgreSQL prompt!

The modern calendar is a trap for the young engineer’s mind. We deal with the calendar on a daily basis and until exposed to its insanity it’s rather common to think that calendar based computations are easy. That’s until you’ve tried to do it once. A very good read about how the current calendar came to be the way it is now is Erik’s Naggum The Long, Painful History of Time.


Business logic is supposed to be the part of the application where you deal with customer or user facing decisions and computations. It is often argued that this part should be well separated from the rest of the technical infrastructure of your code. Of course, SQL and relational database design is meant to support your business cases (or user stories), so then we can ask ourselves if SQL should be part of your business logic implementation. Or actually, how much of your business logic should be SQL?


Sometimes you need to dive in an existing data set that you know very little about. Let’s say we’ve been lucky to have had a high level description of the business case covered by a database, and then access to it. Our next step is figuring out data organisation, content and quality. Our tool box: the world’s most advanced open source database, PostgreSQL, and its Structured Query Language, SQL.


How to Write SQL

Kris Jenkins cooked up a very nice way to embed SQL in your code: YeSQL for Clojure. The main idea is that you should be writing your SQL queries in .sql files in your code repository and maintain them there.

The idea is very good and it is now possible to find alternative implementations of the Clojure yesql library in other languages. Today, we are going to have a look at one of them for the python programming language: anosql.

A recent interview question that I had to review was spelled like this:

Find missing int element into array 1..100

Of course at first read I got it wrong, you have only one integer to look for into the array. So while the obvious idea was to apply classic sorting techniques and minimize array traversal to handle complexity (time and space), it turns out there’s a much simpler way to do it if you remember your math lessons from younger. But is it that much simpler?

Next month, Postgres Open 2014 is happening in Chicago, and I’ll have the pleasure to host a tutorial about PostgreSQL Extensions Writing & Using Postgres Extensions, and a talk aimed at developers wanting to make the best out of PostgreSQL, PostgreSQL for developers:

The tutorial is based on first hand experience on the PostgreSQL Extension Packaging System both as a user and a developer. It’s a series of practical use cases where using extensions will simplify your life a lot, and each of those practical use case is using real world data (thanks to pgloader).

En début de semaine se tenait le PHP Tour 2014 à Lyon, et j’ai eu le privilège d’y être invité afin de présenter comment Utiliser PostgreSQL en 2014.

À l’heure où le NoSQL passe de mode doucement, il est temps de se poser les bonnes questions vis à vis des technologies de bases de données à utiliser, comment et pourquoi. PostgreSQL entre de plein droit dans la case des SGBD relationnels classiques, aussi nous commencerons par étudier ce que de ces outils apportent.

Last week some PostgreSQL users, contributors and advocates have organized a really great conference in Stockholm, Sweden, where I had the please to give the following talk:

PostgreSQL is YeSQL! Nordic PostgreSQL Conference The conference was very well put together and the occasion to meet with plenty of well known PostgreSQL friends and newcomers to the community too. If you were there, I hope you had as much of a good time than I did!

Dimitri Fontaine

PostgreSQL Major Contributor

Open Source Software Engineer

France