How not to change PostgreSQL column type

Your database is ticking along nicely - until a simple DELETE brings it to its knees. What went wrong? While we tend to focus on optimizing SELECT and INSERT operations, we often overlook the hidden complexities of DELETE. Yet, removing unnecessary data is just as critical. Outdated or irrelevant data can bloat your database, degrade performance,...

Whether you are designing a standalone application or a microservice, you will inevitably encounter the topic of sharing identifiers. Whether it’s URLs of web pages, RESTful API resources, JSON documents, CSV exports, or something else, the identifier of specific resources will be exposed. /orders/123 /products/345/variants/1 While an identifier...

Designing a database schema, whether for a new application or a new feature, always raises a lot of questions. The choices you make can have a big impact on how well your database performs and how easy it is to maintain and scale. Whether you’re just getting started with PostgreSQL or consider yourself a seasoned pro, it’s easy to rely on old...

Understanding how comfortable someone is with databases and SQL often comes down to the features they use. In PostgreSQL, one such feature that distinguishes more advanced users is the MERGE command, introduced in version 15 and expanded in version 17 (in beta at the time of writing this article). Before MERGE, developers typically relied on...

Understanding the relationship between data points is crucial. For instance, you might need to identify the most recent orders for each customer or track changes in sensor readings over time. Unlike aggregate functions, which summarise data into a single row, it is window functions that allow you to analyse data while preserving each row’s...