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Re: [PATCH] oidmap: map with OID as key

From
Johannes Schindelin <johannes.schindelin@gmx.de>
Date
Sep 29, 2017, 21:43 UTC
Message-ID
<alpine.DEB.2.21.1.1709292341280.40514@virtualbox>
In-Reply-To
<20170928200556.grysihlj7cbzocfq@sigill.intra.peff.net>
Hi Peff,
On Thu, 28 Sep 2017, Jeff King wrote:
Show 5 quoted lines
> 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

Previous: Jeff KingNext: Jeff King
Message 7 of 16 in “oidmap: map with OID as key”
  1. oidmap: map with OID as keyJonathan Tan, Sep 27, 2017
  2. Brandon WilliamsSep 28, 2017
  3. Jonathan TanSep 28, 2017
  4. Jeff KingSep 28, 2017
  5. Jonathan TanSep 29, 2017
  6. Jeff KingSep 29, 2017
  7. Johannes SchindelinSep 29, 2017
  8. Jeff KingSep 29, 2017
  9. Junio C HamanoSep 28, 2017
  10. Jonathan TanSep 28, 2017
  11. oidmap: map with OID as keyJonathan Tan, Sep 29, 2017
  12. Brandon WilliamsOct 2, 2017
  13. Jeff KingOct 3, 2017
  14. Jonathan TanOct 4, 2017
  15. Jeff KingOct 4, 2017
  16. Junio C HamanoOct 4, 2017

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