PostgreSQL subqueries allow one SQL query to run inside another, making it possible to solve filtering, aggregation, comparison, and table based problems without writing separate queries. The lesson ...

This article is the Japanese version of a post published on STEALIEN's Korean technical blog in December 2022. It introduces ...

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 ...

Microsoft introduced the Query Store when they released SQL Server 2016 and it can track statement performances, pinpoint queries and more. DBTA recently held a webinar focused on the new features and ...

SQL is a convenient way to manage and query your data, but badly written queries can tie up your database. Here are seven common SQL traps and how to avoid them. Database developers have it tough.

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 ...