Comment 2 for bug 85065

I did a few tests against the launchpad_demo database. I did 20 runs of the supermirror_rewritemap.py script, which gave the following average timings:

    4.62 user, 0.30 system, 6.57 elapsed

Hacking the script to prejoin the branch product and owner gave the following average timings:
    4.59 user, 0.29 system, 6.51 elapsed

And removing the call that actually writes the map file (while leaving all the initialisation) gives the following:
    3.21 user, 0.24 system, 6.46 elapsed

So we are talking about a very marginal improvement here. Of course, these numbers don't tell the story of the work done by the database server: it would be doing a lot less work in the second two cases.