[Buildbot] #3480: Change page is very slow when lots of change

[Buildbot trac]

#3480: Change page is very slow when lots of change
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Reporter:  tardyp     |      Owner:
    Type:  undecided  |     Status:  new
Priority:  major      |  Milestone:  0.9.+
 Version:  master     |   Keywords:  simple
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 takes 1.48 second on http://nine.buildbot.net/#/changes
 takes 22 seconds on my instance

 I believe this is because the ordering and limit is not implemented in db
 layer, but in data layer, and change table can grow quite large, so this
 is worth to implement in db layer.

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Ticket URL: <http://trac.buildbot.net/ticket/3480>
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