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* expanding pack idx fanout table
@ 2013-07-08 15:54 Shawn Pearce
  2013-07-08 17:37 ` Junio C Hamano
  2013-07-09  4:19 ` Jeff King
  0 siblings, 2 replies; 4+ messages in thread
From: Shawn Pearce @ 2013-07-08 15:54 UTC (permalink / raw)
  To: git

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.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-07-09  4:19 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-07-08 15:54 expanding pack idx fanout table Shawn Pearce
2013-07-08 17:37 ` Junio C Hamano
2013-07-08 17:58   ` Shawn Pearce
2013-07-09  4:19 ` Jeff King

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