PostgreSQL
SQL and Business Logic
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 …
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YeSQL
78 posts
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 …
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 …