When I first read this question, I thought that although I don't have a checklist, this should be something easy to find. After looking, this may be harder than I thought. We all know that we should be testing basic database functionality (startup/shutdown, export/import, backup/recovery, SQL load utility, Enterprise Manager, SQL*PLUS, listener connectivity, etc) before beginning application testings but I don't have a checklist. Now that you ask, it seems odd that this is hard to find.