87 Articles tagged “YeSQL”

Nearest Big City

6 mins read PostgreSQL, YeSQL
In this article, we want to find the town with the greatest number of inhabitants near a given location. A very localized example We first need to find and import some data, and I found at the following place a CSV listing of french cities with coordinates and population and some numbers of interest for the exercise here. To import the data set, we first need a table, then a COPY command:

The Need For Speed

1 mins read Conferences, PostgreSQLFr-Confs
Hier se tenait la cinquième édition de la conférence organisée par dalibo, où des intervenants extérieurs sont régulièrement invités. Le thème hier était à la fois clair et très vaste : la performance. J’ai eu le plaisir de réaliser une présentation intitulée « The Need for Speed » dans laquelle on replace l’effort d’optimisation dans son contexte métier, afin de faire une étude des coûts et bénéfices et de savoir non seulement à quoi s’attendre mais aussi quand s’arrêter.

Batch Update

5 mins read PostgreSQL, YeSQL

Performance consulting involves some tricks that you have to teach over and over again. One of them is that SQL tends to be so much better at dealing with plenty of rows in a single statement when compared to running as many statements, each one against a single row.

HyperLogLog Unions

2 mins read PostgreSQL, YeSQL
In the article from yesterday we talked about PostgreSQL HyperLogLog with some details. The real magic of that extension has been skimmed over though, and needs another very small article all by itself, in case you missed it. *Which Set Operation do you want for counting unique values?* The first query here has the default level of magic in it, really. What happens is that each time we do an update of the HyperLogLog hash value, we update some data which are allowing us to compute its cardinality.

Dimitri Fontaine

PostgreSQL Major Contributor

Open Source Software Engineer

France