Re: [PATCHv5 00/14] git notes

["Shawn O. Pearce" <spearce@spearce.org>]

Johan Herland <johan@herland.net> wrote:
> Shawn, do you have any additional defence for the date-based fanout?

No.

The only defense I have for it is "it sounds like a nice theory
given access patterns", and the note about memory usage you made,
but which I clipped to keep this email shorter. :-)

It was only a theory I tossed out there in a back-seat-driver
sort of way.  Your results show my hunch was correct, it may help.
But they also say it may not help enough to justify the complexity,
so I now agree with you that SHA-1 fan out may be good enough.

> Are 
> there untested reasonable scenarios that would show the benefits of date-
> based fanout?

I don't think there are, your tests were pretty good at covering
things.

> How does the plan for notes usage in your code-review thingy 
> compare to my test scenario?

I think your tests may still have been too low in volume, 115k notes
isn't a lot.  Based on the distributions I was looking at before,
I could be seeing a growth of >100k notes/year.  Ask me again in
5 years if 115k notes is a lot. :-)

But we all know that SHA-1 distributes data quite well, so the SHA-1
fan-out may just need to change from 2_38 to 2_2_2_34 (or something)
to handle that larger volume.

-- 
Shawn.