Re: [PATCH 0/2] optimizing pack access on "read only" fetch repos

Jeff King [off-list ref] writes:

quoted

quoted

But how do these somewhat mediocre concatenated packs get turned into
real packs?

How do they get processed in a fetch-only repositories that
sometimes run "gc --auto" today?  By runninng "repack -a -d -f"
occasionally, perhaps?

Do we run "repack -adf" regularly? The usual "git gc" procedure will not
use "-f", and without that, we will not even consider making deltas
between objects that were formerly in different packs (but now are in
the same pack).

Correct.  It is not a new problem, and while I think it would need
some solution, the "coalesce 50 small young packs into one" is not
an attempt to address it.

So you are avoiding doing medium-effort packs ("repack -ad") in favor of
doing potentially quick packs, but occasionally doing a big-effort pack
("repack -adf").

So I think "but occasionally" part is not correct.  In either way,
the packs use suboptimal delta, and you have to eventually pack with
"-f", whether you coalesce 50 packs into 1 often or keep paying the
cost of having 50 packs longer.

The trade-off is purely between "one potentially quick coalescing
per fetch in fetch-only repository" vs "any use of the data in the
fetch-only repository (what do they do?  build?  serving gitweb
locally?) has to deal with 25 packs on average, and we still need to
pay medium repack cost every 50 fetches".