Sessionization with Temporal Union

A common problem in web analytics is sessionization or session reconstruction: taking a series of user events and splitting the series into a set of sessions [1]. Often, it is done based solely on the timestamps of the events: a session ends after a certain time of user inactivity. As… Read more →

Welcome Snowflake

Snowflake Computing has recently emerged from stealth with a bold claim of having reinvented the data warehouse. Ease of use is their main motto and I dare to say they live up to this promise. Since one of Snowflake's co-founders, Marcin ┼╗ukowski, is a good friend of mine, I've got… Read more →

A Different Kind of Easy

Putting into words when something will happen is easier than calculating it. This is nothing new. Since 325 CE, Christian Easter falls on "the Sunday after the ecclesiastical full moon." Easy words for hard numbers. Even "next business day shipping " can be hard to crunch. To a human it is… Read more →


The Sapir-Whorf hypothesis (or principle of linguistic relativity) holds that language affects its speakers cognitive process and world view (neo-Whorfianism). Some hold this true even for programming languages, assuming coding in some language implies thinking in that language. K.E. Iverson, inventor of APL, argued that more powerful notations aided… Read more →

Rax/MySQL vs. Rax/Azure vs. Rax/Redshift

Our SQL-backend family is contantly growing. Rax could already connect to SQLite, MySQL and PostgreSQL databases. Now we have also ported Rax to two major cloud databases: Microsoft Azure and AWS Redshift. The port to Azure gave us some headache due to problems with their ODBC driver for Linux. The… Read more →