[LinuxBender]

I am not a DBA but I work with many of them. Most of the DBA's I currently work with have/had Oracle experience, but they are currently supporting MySQL. Some of them also know Postgres. There will always be a need for database engineers and architects. Even knowing how to optimize queries can be quite valuable to a company. Already being an Oracle DBA it should be rather easy for her to pick up the open source databases and widen her career opportunities. IIRC there are even blogs where former Oracle DBA's wrote how-to's that summarize command equivalents for Oracle -> MySQL and Oracle -> Postgres so that if you already know one, you can see the equivalent commands in the corresponding technologies.

As a side note, there are also some git repos that have optimizing scripts for MySQL and Postgres that may also help her learn some of the memory management differences in the other technologies. [1][2] These tools are not perfect, but may be informative.

[1] - https://github.com/jfcoz/postgresqltuner

[2] - https://github.com/major/MySQLTuner-perl