PostgreSQL
Exploring a Data Set in 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 …
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YeSQL
77 posts
PostgreSQL
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 …
PostgreSQL
Find The Missing Integer
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 …
PostgreSQL
PostgreSQL, Aggregates and Histograms
In our previous article Aggregating NBA data, PostgreSQL vs MongoDB we spent time comparing the pretty new MongoDB Aggregation Framework with the decades old SQL …
PostgreSQL
Aggregating NBA data, PostgreSQL vs MongoDB
When reading the article Crunching 30 Years of NBA Data with MongoDB Aggregation I coulnd’t help but think that we’ve been enjoying aggregates in SQL for 3 or …
PostgreSQL
Denormalizing Tags
In our Tour of Extensions today’s article is about advanced tag indexing. We have a great data collection to play with and our goal today is to be able to quickly …
PostgreSQL
PostgreSQL Autonomous Transaction
PostgreSQL is an all round impressive Relational DataBase Management System which implements the SQL standard (see the very useful reference page Comparison of different …
PostgreSQL
Using trigrams against typos
In our ongoing Tour of Extensions we played with earth distance in How far is the nearest pub? then with hstore in a series about trigger, first to generalize Trigger …
PostgreSQL
Auditing Changes with Hstore
In a previous article about Trigger Parameters we have been using the extension hstore in order to compute some extra field in our records, where the fields used both for …
PostgreSQL
Trigger Parameters
Sometimes you want to compute values automatically at INSERT time, like for example a duration column out of a start and an end column, both timestamptz. It’s easy …
PostgreSQL
Understanding Window Functions
There was SQL before window functions and SQL after window functions: that’s how powerful this tool is. Being that of a deal breaker unfortunately means that it can …
PostgreSQL
How far is the nearest pub?
In our recent article about The Most Popular Pub Names we did have a look at how to find the pubs nearby, but didn’t compute the distance in between that pub and …