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From: Dave Borowitz <dborowitz@google.com>
To: Shawn Pearce <spearce@spearce.org>
Cc: Michael Haggerty <mhagger@alum.mit.edu>, git <git@vger.kernel.org>
Subject: Re: reftable: new ref storage format
Date: Sun, 16 Jul 2017 17:13:51 -0400	[thread overview]
Message-ID: <CAD0k6qSpNTWkn-97nQQ1DJrh=sd3dppTXytfbafqj-eVsWDTFg@mail.gmail.com> (raw)
In-Reply-To: <CAJo=hJv36tYuxHuso7NrPkfE9hApGfn=iP8g_8+MeM8L91h09g@mail.gmail.com>

On Sun, Jul 16, 2017 at 3:43 PM, Shawn Pearce <spearce@spearce.org> wrote:
> True... but... in my "android" example repository we have 866,456 live
> refs. A block size of 64k needs only 443 blocks, and a 12k index, to
> get the file to compress to 28M (vs. 62M packed-refs).
>
> Index records are averaging 28 bytes per block. That gives us room for
> about 1955 blocks, or 4,574,700 refs before the index block exceeds
> 64k.

That's only a 5x increase over the current number of refs in this
android repo. I would not be so sure this repo doesn't grow another 5x
in the next few years. Especially as the other optimizations for
working with large repos start to be applied, so it won't be
prohibitively painful to work with such a repo.

Are we ok with increasing the block size when this eventually happens?
(At least I think that's what we would have to do, I haven't been
following closely the discussion on scaling limits.)

  parent reply	other threads:[~2017-07-16 21:14 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-13  0:17 reftable: new ref storage format Shawn Pearce
2017-07-13 19:32 ` Jeff King
2017-07-13 19:56   ` Stefan Beller
2017-07-13 20:35     ` Jeff King
2017-07-13 21:51       ` Eric Wong
2017-07-14  0:27       ` Shawn Pearce
2017-07-14 20:10         ` Jeff King
2017-07-14  0:11   ` Shawn Pearce
2017-07-14 14:27     ` Dave Borowitz
2017-07-14 15:31       ` Shawn Pearce
2017-07-14 20:08     ` Jeff King
2017-07-16  6:01       ` Shawn Pearce
2017-07-16 10:01         ` Jeff King
2017-07-16  8:07       ` Johannes Sixt
2017-07-16 10:03         ` Jeff King
2017-07-16 10:10           ` Johannes Sixt
2017-07-16 17:33 ` Michael Haggerty
2017-07-16 19:43   ` Shawn Pearce
2017-07-16 21:12     ` Shawn Pearce
2017-07-16 21:13     ` Dave Borowitz [this message]
2017-07-16 21:31       ` Shawn Pearce
2017-07-18  1:43     ` Michael Haggerty
2017-07-18 18:53       ` Junio C Hamano
2017-07-23 22:56       ` Shawn Pearce
2017-07-23 23:03         ` Shawn Pearce

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