From: Jeff King <peff@peff.net>
To: Jon Smirl <jonsmirl@gmail.com>
Cc: Andreas Ericsson <ae@op5.se>, Git Mailing List <git@vger.kernel.org>
Subject: Re: Git's database structure
Date: Tue, 4 Sep 2007 13:09:22 -0400 [thread overview]
Message-ID: <20070904170921.GA31300@coredump.intra.peff.net> (raw)
In-Reply-To: <9e4733910709040919u3d252b91s2785ed4d20086c88@mail.gmail.com>
On Tue, Sep 04, 2007 at 12:19:33PM -0400, Jon Smirl wrote:
> By introducing tree nodes you have blended a specific indexing scheme
> into the data. There are many other ways the path names could be
> indexed hash tables, binary trees, etc.
That is correct. However, given that indexing scheme, many of the common
operations just "fall out" simply and efficiently, without the need to
keep separate indices. So yes, git is geared towards a particular set of
operations.
Your complaint seems to be two-fold:
1. there is an inelegance in the blending of data and indexing. The
problem with changing this is:
a. we are all already using git, and it would require completely
re-vamping the core data structure
b. there is some feeling that the blending is necessary for
performance. Given the difficulty of (a), I think you would
have to provide compelling evidence (i.e., numbers) that a
git-like system based around set theory with separate indices
would perform as well.
2. you want perform some operations to which the hierarchy is not
well-suited. In this case, I think you can get by with the same
solution you have proposed already: indices external to the data
structure (in fact, this is exactly what Google is doing: taking
hierarchical URLs and indexing them in different ways).
Have you taken a look at the pack v4 work by Shawn and Nicolas? It
is an attempt to build such indices at pack time (but keeping the
core git data structure intact).
-Peff
next prev parent reply other threads:[~2007-09-04 17:09 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-04 15:23 Git's database structure Jon Smirl
2007-09-04 15:55 ` Andreas Ericsson
2007-09-04 16:07 ` Mike Hommey
2007-09-04 16:10 ` Andreas Ericsson
2007-09-04 16:19 ` Jon Smirl
2007-09-04 16:29 ` Andreas Ericsson
2007-09-04 17:09 ` Jeff King [this message]
2007-09-04 20:17 ` David Tweed
2007-09-04 17:21 ` Junio C Hamano
2007-09-04 16:28 ` Jon Smirl
2007-09-04 16:31 ` Andreas Ericsson
2007-09-04 16:47 ` Jon Smirl
2007-09-04 16:51 ` Andreas Ericsson
2007-09-04 17:25 ` Junio C Hamano
2007-09-04 17:44 ` Jon Smirl
2007-09-04 18:04 ` Mike Hommey
2007-09-04 19:44 ` Reece Dunn
2007-09-04 18:06 ` Junio C Hamano
2007-09-04 21:25 ` Theodore Tso
2007-09-04 21:54 ` Jon Smirl
2007-09-05 7:18 ` Andreas Ericsson
2007-09-05 13:41 ` Jon Smirl
2007-09-05 14:51 ` Andreas Ericsson
2007-09-05 15:37 ` Jon Smirl
2007-09-05 15:54 ` Julian Phillips
2007-09-05 16:12 ` Jon Smirl
2007-09-05 17:31 ` Julian Phillips
2007-09-06 1:27 ` Kyle Moffett
2007-09-05 17:39 ` Mike Hommey
2007-09-06 8:49 ` Andreas Ericsson
2007-09-06 9:09 ` Junio C Hamano
2007-09-06 11:03 ` Wincent Colaiuta
2007-09-06 12:56 ` Johannes Schindelin
2007-09-06 18:14 ` Steven Grimm
2007-09-07 0:33 ` Martin Langhoff
2007-09-05 19:52 ` Andy Parkins
2007-09-04 17:19 ` Julian Phillips
2007-09-04 17:30 ` Jon Smirl
2007-09-04 18:51 ` Andreas Ericsson
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