Improved vacuum in PostgreSQL 13
Among modern successful RDBMSes employing MVCC only PosgreSQL (correct me if I'm wrong) stores stale row versions on the page. Other vendors store them in some physically separate place (tempdb in MSSQL, UNDO tablespace in Oracle, etc.) This reduces both regular read (scans) and write (page splits) I/O and eliminates the need to vacuum (more I/O).<p>Of course this approach requires some maintenance of that separate place. But such maintenance doesn't compete for I/O with regular workload and doesn't hurt performance.<p>So after decades of progress and improvement it looks like this latter approach turned out to be more efficient and is winning historically.