See [microdnf repository](https://github.com/rpm-software-management/microdnf) and [man page](https://www.mankier.com/8/microdnf). It's included in [oraclelinux:8-slim container image](https://github.com/oracle/container-images#differences-between-oraclelinux8-and-oraclelinux8-slim).
See microdnf repository and man page. It's included in oraclelinux:8-slim container image.