From: Shawn Pearce <spearce@spearce.org>
To: git <git@vger.kernel.org>
Subject: expanding pack idx fanout table
Date: Mon, 8 Jul 2013 08:54:24 -0700 [thread overview]
Message-ID: <CAJo=hJsto1ik=GTC8c3+2_jBuUqcAPL0UWp-1uoYYMpgbLB+qg@mail.gmail.com> (raw)
Has anyone studied the impact of converting the pack idx fanout table
from 256 entries to 65536 entries?
Back of the envelope estimates for 3.1M objects in linux.git suggests
a 2^16 fanout table would decrease the number of binary search
iterations from ~14 to ~6. The increased table costs an extra 255 KiB
of disk. On a 70M idx file this is noise.
I'm starting to wonder if increasing the fanout table once the object
count is above a certain threshold is a reasonable optimization for
larger repositories.
next reply other threads:[~2013-07-08 15:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-08 15:54 Shawn Pearce [this message]
2013-07-08 17:37 ` expanding pack idx fanout table Junio C Hamano
2013-07-08 17:58 ` Shawn Pearce
2013-07-09 4:19 ` Jeff King
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