Google heavy promotes articles that use their Google Analytics and have high time-on-page scores. Everything Google does with search ranking is gameable but built to focus on high quality content. The best thing about having a couple high ranking pages is that it becomes much easier to make others. Your trust score is already high so there's a good chance other articles about postgres will also reach first page, even if they're not about specialized topics. This is what the SEOtards fail to understand