PostgreSQL puts the pedal to the metal with some smart indexing tweaks in version 12
https://www.theregister.co.uk/2019/10/04/postgresql_12/
Open-source database darling PostgreSQL emitted a new version of its eponymous database last night with more nods to standard SQL and a performance boost.
The performance gains can be attributed to improvements in the indexing system as well as to partitioning. Frequently modified B-tree indexes have been optimised and the team claims a 40 per cent reduction in space utilisation.