Subject: Re: [GSoC] Designing a faster index format - Progress report week 13

From: Thomas Rast <[email-masked]>
Date: Wed, 25 Jul 2012 08:44:10 +0200

Junio C Hamano <[email-masked]> writes:

> Thomas Rast <[email-masked]> writes:
>
>> Junio's index-v4 was a speed boost mainly because it cuts down on the
>> size of the index.  Do we want to throw that out?
>
> That's pretty much orthogonal, isn't it?
>
> The index-v4 is merely to show how a stupid prefix compression of
> pathnames without nothing else would reduce the file size and I/O
> cost, in order to set the bar for anything more clever than that.
>
> I thought that this discussion is about keeping, squishing, or
> discarding part of the cached stat info, and nobody is suggesting
> what to do with the prefix compression of pathnames.

True, sorry for being so confusing.  'Throw "that" out' was meant to
refer to the observation that smaller indexes are generally faster.

Whether this matters in the long run is another question.  Perhaps
partial loading combined with something like inotify can avoid full
reads in most operations.

-- 
Thomas Rast
trast@{inf,student}.ethz.ch