Better "hot patching" on 11.2.0.2

I had missed this info: With Oracle version 11.2.0.2 it's much less likely to disrupt sessions that are using packages that are recompiled in another session:

Package Treated as Stateless if State is Constant for Life of Session

Before Release 11.2.0.2, if a session recompiled the body of a stateful package, and then another session that had instantiated that package referenced it, the latter session got the severely disruptive error ORA-04068 (“existing state of packages … has been discarded”). Therefore, "hot patching" packages was likely to disrupt their users.
As of Release 11.2.0.2, Oracle Database treats a package as stateless if its state is constant for the life of a session (or longer). This is the case for a package whose items are all compile-time constants.(...)