“Patching” is a good way to think about it. Thank you both for the clarifications.
Greg, you are spot-on regarding my use-case. I have been contributing to OSM and enjoy checking them in OSMAnd shortly after. On Friday, March 8, 2019 at 7:40:02 AM UTC-8, Greg Troxel wrote: > > Malcolm Smith <[email protected] <javascript:>> writes: > > > I am a little unclear about the relationship between my OSMAnd Live maps > > and downloaded maps. As shown in the screenshots below, I updated both > > maps and then compared the dates. My Live USA-CA map shows a last > update > > of March 6th, while my downloaded USA-CA map shows January 31st. Is > this > > how it's supposed to work or is my downloaded map redundant? Which map > > version am I seeing when I browse the map? Which version would I see if > I > > lost my internet connection? > > In addition to what Jack said: "live" does not mean online. First, you > get a map for an area. These are updated monthly, typically appearing > around the 9th with a data date of the last day of the previous month > (which is awesome freshness to start with). These large files are > actually transferred to your phone. > > Then, whe you turn on "live updates", your phone periodically fetches > patch files that have changes from your map's date to very recently. > These files are also stored on your phone. > > I have noticed that configuring live updates to run daily, and only on > wifi, leads to them not happening; I'm not sure if there is a background > service. So, when I care about freshness, before leaving wifi, I do a > manual 'update now' for the map for my state. > > Live updates are useful for multiple reasons: > > By getting them, you can avoid redownloading the main map so often. > > Your map is more up to date for general use. But usually not much > happens in a month, and navigation with data that's 30 days old is > hard to distinguish from data a few hours old. The gaps between > reality and the osm database are bigger than those changes, usually. > But people are updating road closures more now. > > If you are contribuing to OSM, you might add as much as you can from > aerials for an area you are going to visit. You then want to see that > as a basis for taking notes for further edits. > > If you are visiting someplace you haven't been, you might want to > spiff up the map months ahead of time so you can use the new data. > But you might not get to it until closer to the time. It's actually > feasible to edit OSM, wait two hours, and then update OSMAnd, usually. > -- You received this message because you are subscribed to the Google Groups "Osmand" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
