From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Jeff King <peff@peff.net>
Cc: Jonathan Tan <jonathantanmy@google.com>,
Brandon Williams <bmwill@google.com>,
git@vger.kernel.org, git@jeffhostetler.com
Subject: Re: [PATCH] oidmap: map with OID as key
Date: Fri, 29 Sep 2017 23:43:57 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1.1709292341280.40514@virtualbox> (raw)
In-Reply-To: <20170928200556.grysihlj7cbzocfq@sigill.intra.peff.net>
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
next prev parent reply other threads:[~2017-09-29 21:44 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-27 22:19 [PATCH] oidmap: map with OID as key Jonathan Tan
2017-09-28 0:41 ` Brandon Williams
2017-09-28 17:46 ` Jonathan Tan
2017-09-28 20:05 ` Jeff King
2017-09-29 19:04 ` Jonathan Tan
2017-09-29 19:26 ` Jeff King
2017-09-29 21:43 ` Johannes Schindelin [this message]
2017-09-29 23:24 ` Jeff King
2017-09-28 3:13 ` Junio C Hamano
2017-09-28 17:38 ` Jonathan Tan
2017-09-29 22:54 ` [PATCH v2] " Jonathan Tan
2017-10-02 23:48 ` Brandon Williams
2017-10-03 6:31 ` Jeff King
2017-10-04 0:29 ` Jonathan Tan
2017-10-04 7:45 ` Jeff King
2017-10-04 8:48 ` Junio C Hamano
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