Re: Git Scaling: What factors most affect Git performance for a large repo?

["brian m. carlson" <sandals@crustytoothpaste.net>]

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On Fri, Feb 20, 2015 at 11:06:44AM -0500, Stephen Morton wrote:
>2. I'd not heard about bitmap indexes before this thread but it sounds
>like they should help me. In limited searching I can't find much
>useful documentation about them. It is also not clear to me if I have
>to explicitly run "git repack --write-bitmap-indexes" or if git will
>automatically detect when they're needed; first experiments seem to
>indicate that I need to explicitly generate them. I assume that once
>the index is there, git will just use it automatically.

Pack bitmaps are a way of speeding up clones and fetches by precomputing 
reachability information.  Practically, this means that the initial 
"Counting objects" phase is instantaneous for clones and much faster for 
fetches.

The way I've done it in the past is to set repack.writeBitmaps = true in 
/etc/gitconfig on the server.  (I highly recommend enabling reflogs in 
the same place.)  Then you'll need to ensure that git gc runs 
periodically so that bitmaps are generated.
-- 
brian m. carlson / brian with sandals: Houston, Texas, US
+1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only
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