Sounds like you need multi-versioned views to do this. However, I don't think you can have multi-version views on non-saved edits. Edits in ArcSDE get written to the delta tables. However, in some cases the features may already be deleted, some changed, others created, the changes don't make it to the base tables until a compress. Editing geodatabase data using sql is kind of a gamble, it is fast and works great until it corrupts your entire database. There are ways to make bulk updates faster, (updatecursor, Itablewrite, loadonly) but none of them really come close to using an sql update. If this is a once in a while kind of update, I suggest, closing all edit sessions, reconciling all outstanding versions, compressing the table or featureclass, then running the sql script.