John,
Following on to Adam's excellent response, an almost ubiquitous requirement is to persist things like database account passwords, application account passwords, and database objects such as Oracle "database links" across a refresh operation. These are normally set immediately following the initial provisioning of a VDB, and it is a hassle to have to re-set them manually each time a refresh is performed.
Some of my colleagues within Delphix have begun posting code samples on Github.com, and I have resolved to do so as well, but I'm a little behind on it, so instead...
If you'd like some sample UNIX/Linux shell-scripts for persisting Oracle database account passwords and Oracle database link definitions across refresh using Pre-Refresh and Post-Refresh hooks, then I'd be glad to share GDrive links to download them here (i.e. "
ora_vdb_prerefresh.sh" and "
ora_vdb_postrefresh.sh"). NOTE: these scripts are just example code with no warranty whatsoever; use at your own risk, and it is unlikely that you'll find them useful if you don't modify them to fit your local standards.
Hope this helps!
-Tim