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

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 ...

Out of all the programming languages you need to learn in the IT industry, SQL is one of the most important. SQL is so integral to modern big data access and organization processes that it’s never a ...

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 ...