PostgreSQL query optimization with CREATE STATISTICS is an important topic. Usually, the PostgreSQL optimizer (query planner) does an excellent job. This is not only true for OLTP but also for data warehousing. However, in some cases the optimizer simply lacks the information to do its job properly. One of these situations has to do with […]

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 […]