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To: phillips@innominate.de
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In-Reply-To: <01022208282404.25968@gimli> (message from Daniel Phillips on
	Thu, 22 Feb 2001 08:24:08 +0100)
Subject: Re: [Ext2-devel] [rfc] Near-constant time directory index for Ext2
From: tytso@valinux.com
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Date: Thu, 22 Feb 2001 05:20:10 -0800
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   From: Daniel Phillips <phillips@innominate.de>
   Date: Thu, 22 Feb 2001 08:24:08 +0100
   Content-Type: text/plain

   > Is it worth it?  Well, it means you lose an index entry from each
   > directory block, thus reducing your fanout at each node of the tree by a
   > worse case of 0.7% in the worst case (1k blocksize) and 0.2% if you're
   > using 4k blocksizes.

   I'll leave that up to somebody else - we now have two alternatives, the
   100%, no-compromise INCOMPAT solution, and the slightly-bruised but
   still largely intact forward compatible solution.  I'll maintain both
   solutions for now code so it's just as easy to choose either in the end.

Well, the $64,000 question is exactly how much performance does it cost?
My guess is that it will be barely measurable, but only benchmarks will
answer that question.

							- Ted
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