Update - Cobalt v.8.623 Stable
Here is the new version of Cobalt 8.623.
This version contain performance improvements. Although that was targeted as Cobalt 9 feature, it is 50% implemented in this new version. There will be still some improvements in Cobalt 9.
We had a case study with 300k articles and 1.5m fields values. The site we were working on took 17000ms just for SQL queries. Now all SQL queries are only 300ms. To achieve such a performance, of course you have to follow some principles, and I'll post case study