[Rd] what is the preferred method to create a package local variable?

[Whit Armstrong]

for the moment, I'm using:

.onAttach <- function(libname, pkgname) {
    .bbg.db.conn <<- dbConnect(dbDriver("PostgreSQL"), user="blah","blah")
}

.onUnload <- function(libpath) {
    dbDisconnect(.bbg.db.conn)
}


which results in a hidden global variable in the global environment.

I would prefer to make the assignment only in the package namespace.
I've looked at assignInNamespace, but I can't seem to make it work.

Is there a preferred method for doing this?

When I try adding an assignment directly in the source file, I get the
"cannot change value of locked binding" error.

What am I missing?

Thanks,
Whit