PostgreSQL query tuning is our daily bread at Cybertec, and once you have done some of that, you’ll start bristling whenever you see an OR in a query, because they are usually the cause for bad query performance. Of course there is a reason why there is an OR in SQL, and if you […]

While doing PostgreSQL consulting for a German client, I stumbled over an interesting issue this week, which might be worth sharing with some folks out on the Internet, it’s all about grouping. Suppose you are measuring the same thing various times on different sensors every, say, 15 minutes. Maybe some temperature, some air pressure or […]