Will I have to rewrite my code if I upgrade to R6?

You mentioned that LSXODBC will not be supported in R6. I am currently using LS:DO to connect to my relational backend with R5. If LSXODBC/LS:DO will not be supported, what are my options? Do I have to go back and rewrite my code if we were to upgrade to R6?

Is it possible to start using LC LSX in R5?
I don't know of a plan to end support for LS:DO. I believe what I said that you might have misunderstood, is that LSXLEI is not supported in Notes 6 -- its functionality has been merged into the LC LSX. Your LS:DO code should continue to work in Notes 6.

However, you might want to convert it to use the LC LSX anyway, just because it's likely to be faster, and because the code is likely to be a lot simpler than the LS:DO implementation, since your code doesn't need to format every operation as a SQL statement.