A couple days ago when writing a separate email I came across this DataStax blog post discussing MVs [1]. Imagine my surprise when I noticed the date was five years ago...
While at TLP, I helped numerous customers move off of MVs, mostly because they affected stability of clusters in a horrific way. The most telling project involved helping someone create new tables to manage 1GB of data because the views performed so poorly they made the cluster unresponsive and unusable. Despite being around for five years, they've seen very little improvement that makes them usable for non trivial, non laptop workloads. Since the original commits, it doesn't look like there's been much work to improve them, and they're yet another feature I ended up saying "just don't use". I haven't heard any plans to improve them in any meaningful way - either to address their issues with performance or the inability to repair them. The original contributor of MVs (Carl Yeksigian) seems to have disappeared from the project, meaning we have a broken feature without a maintainer, and no plans to fix it. As we move forward with the 4.0 release, we should consider this an opportunity to deprecate materialized views, and remove them in 5.0. We should take this opportunity to learn from the mistake and raise the bar for new features to undergo a much more thorough run the wringer before merging. I'm curious what folks think - am I way off base here? Am I missing a JIRA that can magically fix the issues with performance, availability & correctness? [1] https://www.datastax.com/blog/2015/06/new-cassandra-30-materialized-views [2] https://issues.apache.org/jira/browse/CASSANDRA-6477
