Fedora Looking To Transition The RPM Database From Berkeley DB To SQLite
As a move ultimately for Red Hat Enterprise Linux as well, Red Hat developers working on Fedora are planning to transition the RPM database (RPMDB) away from the long-standing Berkeley DB to using SQLite.
Since Oracle's acquisition of Berkeley DB developer Sleepycat Software in 2006, Berkeley DB's 6.0 release and newer has been under an AGPL license and commercial license rather than their previous free software license. That dual license change has kept RPMDB back on Berkeley DB even while the latest upstream of Berkeley DB is version 18.1.
Moving off the aging Berkeley DB 5 is long overdue but for Fedora 33 later this year might finally happen and a full transition away by Fedora 32 in one year's time.
In place of Berkeley DB, developers are looking at moving to the RPM database over to using SQLite. This ultimately should lead to a more robust RPM database as well once fully implemented and making use of SQLite's modern features.
More details on the RPMDB SQLite transition plans via this Wiki page. Also for Fedora 33 the plan is making use of RPM 4.16. With RPM 4.16 is the initial experimental SQLite back-end, an improved expression parser, SSD detection and optimization, and other features.