Hello, Maxime Petazzoni wrote: > A > very simple hourly crontab could be created from this. We'd have to > check of course that this process has a significant time advantage. I > believe the more frequent we make the update process, the faster it > could run: I don't think the processing time grows linearly with the > update interval (aka it takes way longer than 60 times what it takes to > process a minute diff to process an hourly diff).
It would be very interesting to have some benchmarks about this. At first I was dubitative about that claim, but on second thoughts, maybe it's right (startup overhead higher, but working sets smaller on the other hand => scan/search/sort overheads perhaps smaller). The only closely-related benchmark I'm aware of is http://lists.openstreetmap.org/pipermail/talk-fr/2010-May/021293.html (thanks, Thomas), do you know of any other tests with osmosis in the loop ? To test this... Is there a "COW" feature for pgsql which would allow us to run a few tests with the prod DB, without altering the data delivered to ocitysmap ? If not, I'm afraid we'd have to test on another machine. Regards,
