PostgreSQL subqueries allow one SQL query to run inside another, making it possible to solve filtering, aggregation, ...

Let's break down when it's ideal to use the NOLOCK hint and when you should never use it. As a consultant, I work on wide swaths of database systems, which means I get to see many, many SQL statements ...

When working as an engineer, you will surprisingly often have opportunities to interact with databases. From application ...

PostgreSQL CASE statements make it possible to add conditional logic directly into SQL queries, working similarly to IF ELSE statements in programming languages and spreadsheet tools. This tutorial ...

On Aug. 8, 2012, a group of engineers at Facebook started the Presto project, introducing a new SQL query engine to help the social media giant to scale. After a decade of growth, the technology is ...

I've been playing around with the new Microsoft service, currently in preview and it's time to show off what it can do. Have you ever struggled with a database performance problem or ever struggled to ...

A common SQL habit is to use SELECT * on a query, because it’s tedious to list all the columns you need. Plus, sometimes those columns may change over time, so why not just do things the easy way? But ...

Here's a look at different ways to query Hadoop via SQL, some of which are part of the latest edition of MapR's Hadoop distribution SQL: old and busted. Hadoop: new hotness. That’s the conventional ...