Re: [PATCH] oidmap: map with OID as key

Hi Peff,

On Thu, 28 Sep 2017, Jeff King wrote:

If you're planning on using an oidset to mark every object in a
100-million-object monorepo, we'd probably care more. But I'd venture to
say that any scheme which involves generating that hash table on the fly
is doing it wrong. At at that scale we'd want to look at compact
mmap-able on-disk representations.

Or maybe you would look at a *not-so-compact* mmap()able on-disk
representation, to allow for painless updates.

You really will want to avoid having to write out large files just because
a small part of them changed. We learn that lesson the hard way, from
having to write 350MB worth of .git/index for every single, painful `git
add` operation.

Ciao,
Dscho