Hi there. CEO of Tablespace here. We have indeed made something that people can try ;) We built a Columnstore index for Postgres which allows users to run fast OLAP analytics on Postgres. We just launched in open beta and are looking for feedback, comments, questions. The blog post is a comparison of Tablespace vs. ClickHouse for OLAP workloads. We also included links to the benchmark scripts that people can run themselves as well.
You can post the blog post as a regular submission, you can post whatever it is you want people to try as a Show HN, you can't post a blog post as a Show HN. That's in the thing I linked:
Off topic: blog posts, sign-up pages, newsletters, lists, and other reading material. Those can't be tried out, so can't be Show HNs. Make a regular submission instead.