Achieving Sub Second SQL JOINs and building a data warehouse using Spark, Cassandra, and FiloDB

Evan loves to design, build, and improve bleeding edge distributed data and backend systems using the latest in open source…

Read More »

SQL JOIN or EXISTS? Chances Are, You’re Doing it Wrong

I’ve noticed this very consistently with a lot of customers, and also with participants of our Data Geekery SQL Workshop…

Read More »

SQL: Counting Groups of Rows Sharing Common Column Values

In this post, I focus on using simple SQL SELECT statements to count the number of rows in a table…

Read More »

jOOQ Tuesdays: Glenn Paulley Gives Insight into SQL’s History

Welcome to the jOOQ Tuesdays series. In this series, we’ll publish an article on the third Tuesday every other month…

Read More »

How to Evolve from RDBMS to NoSQL + SQL

For the past 25 years, applications have been built using an RDBMS with a predefined schema that forces data to…

Read More »

How to Detect Slow Queries with jOOQ

Just now, we implemented a nice little feature in jOOQ’s code generator: https://github.com/jOOQ/jOOQ/issues/4974 It detects whenever the jOOQ code generator…

Read More »

Impress Your Coworkers by Using SQL UNPIVOT!

I’ve recently encountered a very interesting question on Stack Overflow by an unnamed user. The question was about generating a…

Read More »

Oracle LONG and LONG RAW Causing “Stream has already been closed” Exception

Like many old databases, Oracle has legacy data types, which are rather nasty to work with in every day SQL.…

Read More »

How to Fill Sparse Data With the Previous Non-Empty Value in SQL

The following is a very common problem in all data related technologies and we’re going to look into two very…

Read More »