I’ve been doing some work recently that involved the use of Materialised Views on Oracle 11g (11.1.0.7), particularly around PCT refresh. There are some things that are not clear from the documentation, or are actually bugs so far as I’m concerned, and I’ve detailed these below. In this example I was working on part of a DWH with c.2 millions rows aggregated up daily. One of the things that I spent a long time trying to get to work was Partition Truncation when using PCT refresh.