Re: LMDB and Referential transparency

Pierre-Étienne Meunier wrote:

Hi,

I love LMDB, thanks for writing it!

You're welcome.

I wonder whether it would be possibly to add the following feature:

When I change one of the databases (called for instance A) in my environment, I'd like to be able to still keep a copy of A as it was before, and make a new copy B, that would share all its memory with A, except the changes.

Not likely to happen. The change you're suggesting would require adding a reference counter to every page, among other things. The cost of such a change would be quite high, not worth it for a very obscure feature.