Great writeup but it was a bit weird that the choice was Postgres vs Cassandra... Those are two very different projects.<p>> Recently I was conducting an evaluation of several different databases for a messaging workload.<p>> While PostgreSQL was a strong contender among SQL databases and had given good results in early experiments, I was looking for the ideal NoSQL candidate.<p>Maybe I just don't know much about these projects but is Cassandra a common choice for a messaging workload? Postgres also strikes me as a weird choice -- you're going to need to do some partitioning (or use a plugins like timescale and/or citus) to make things scale gracefully (not web scale per-say, but just reasonably active messaging over a long period of time).<p>I got some inside information that LINE (a popular messaging app here in Japan) has a large Kafka cluster -- maybe it's 100+ nodes by now.<p>In the end I do love me some postgres propaganda though, it's a fantastic tool -- IMO the best RDBMS out there, and maybe even better for some usecases you wouldn't expect.<p>On the Cassandra front, A bit disappointing to hear about the issues uptaking the patch. This kind of improvement seems well worth reviewing, but the priority is low., I do wonder where Scylla[0] would have been on the spectrum of performance.<p>[EDIT] - It looks like cassandra trunk wins on the margins[1], despite this speed up, so it's not so cut and dry.<p>[0]: <a href="https://www.datasciencecentral.com/profiles/blogs/scylla-vs-cassandra-performance-comparison" rel="nofollow">https://www.datasciencecentral.com/profiles/blogs/scylla-vs-...</a><p>[1]: <a href="https://issues.apache.org/jira/browse/CASSANDRA-16499?focusedCommentId=17301900&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17301900" rel="nofollow">https://issues.apache.org/jira/browse/CASSANDRA-16499?focuse...</a>