[MANUAL] - using SQL map files bigger then 2GB

[Menion]

this is really weird. May you just do some test? Just create two small maps of any area. Best same area but different zoom. And then put them into one directory. If this will not work, please send them to me on email or if they'll be bigger, then thanks to some service, rapidshare, dropbox, whatever ...

[MedoMys]

Created 2 maps, moved to subdirectory, invisible ...
I've sent you these maps.

[Menion]

I'm stupid, sorry!! Problem is only two maps in directory. When you add third, all will works!!

Fixed and will be tomorrow in testing version ...

[suamikim]

Hi there!

I've been following this thread with high interest and have an idea:

Have you ever considered supporting the AndNav-Format for stored offline-maps?
I know that the Geocaching-App GeOrg supports it and that mobac can create them too.

Because of the fact, that AndNav-Maps are based on single files (every tile in the map is represented by one file) there are some advantages towards the sqlite-database-files:

• There are no limitations when it comes to single files (2 GB for Android as discussed in this thread, 4 GB for FAT-Formated SD-Cards, ...) because obviously there will never be 1 single file that big
• One can download large areas in mobac with high zoom-levels in multiple steps (if necessary because of the 500.000 tiles limitation in mobac) and still handle it as 1 map.
  I'm gonna explain this point a little more in detail later with an example.
• Those maps would also be supported by GeOrg.
  I know that this isn't exactly an advantage from your point of view but I do need both programs and would love to have one map-base for both of them.
  Actually GeOrg is also able to read the same sqlite-maps as Locus does but it's not able to load 2 maps at a time what would be necessary if a map is larger than 2 GB (as discussed in this thread)...
  Please let me know if it's not clear what i mean with this point. It's a little hard to explain.

One disadvantage that i can think of is that the handling of so many single small files could be a problem for the performance. At least in comparison with databases I'm pretty sure that the performance would decrease a little but as much as i can tell GeOrg is able to handle large AndNav-Maps pretty well so either it's not really that big a deal with the performance or they have pretty good algorithms to handle those maps...

Finally I got to admit that I'm not too familiar with the design of your app and how much work it would be to support AndNav-Maps but maybe i was able to give you some new input and a new idea on how to solve the problem with bigger maps...

Thanks & best regards!

[marlar]

Hi,

FYI, Locus can already handle a format much similar to what you describe. It is called TAR format and is also supported by mobac. Each tile is a different file just as you sketch above.

It works well and the performance is fine enough. The downside is that it takes ages to copy the files to the phone. Virtually hours for big maps as opposed to minutes for similar sqlite based maps. And if you want to the delete the maps from the phone, it takes ages too!

For that reason I prefer sqlite based maps.

[Menion]

I'll think about it later but as marlar say, there is no advantage with Andnav format! It slow, it takes too much disk space, it's really terrible to copy on card or delete. And do something like this just for "better" support for Georg? No thanks. If Georg use Locus map format, so just create few smaller maps (smaller then 2GB) and use them ...

[suchuaato]

Hi Menion,
regarding rmaps, I set my RMaps directory to where the locus directory is and it did treat all of the maps as one big one,
 but currently I only have 1.9 GB of maps in 6 separate sqlitedb maps  so not over the total 2 gb limit yet,
am creating some more maps for locus will let you know what happens
Stuart

Heh, 14GB seems to be good but unfortunately as you can see, this is not in my power!

so with this troubles, comes two questions!
1) which is maximum size allowed to read correctly and why is this limit!
2) is here any other solution on this problem? Maybe some special format with separated files working all together ...

anyway ... did anyone tried this huge maps on any other supported software how they handle them? RMaps for example ...

[suamikim]

Ok, i just realized how much more disk-space those single files actually need then a single one. Therefore the AndNav-Format is no option for me neither ;(

But there's one question left for me:
How do you guys manage to create maps with mobac smaller than 2 GB. The problem for me is that the software doesn't display how large the resulting file would be.
The only way I can think of is to approximate the size by the number of selected tiles, but (obviously) 1 tile has not always the same size...

To clarify this a little bit I've just created 2 maps with a nearly similar number of tiles:

1. Center of London: 3546 tiles -> Resulting sqlite-db 56,7 MB (approx. 16,6 Bytes per tile)
2. Somewhere in Panama (partly city, partly forest): 3592 tiles -> Resulting sqlite-db 10.7 MB (approx. 3 Bytes per tile)

How do i know now before creating the map how to choose the zoom-levels and the size of the selected region to not exceed the 2 GB limit in the resulting file?
Trial and error is definitely not the way to go because on one hand the download of large maps with mobac takes pretty long and on the other hand it produces a lot of trafic on the servers...

Thanks, for every advice on this topic!

[xxc]

Hi Menion,
What appends if the cached map files (the ones in locus/mapsOnline ) become bigger than 2Gb ?
One of my file is growing and will soon reach 2Gb!
Thanks
Vincent

[Menion]

hi,
  very probably will stop works correctly. When android send request to SQLite database bigger then 2GB, I noticed that there is big chance that this call return no tile, random tile, correct tile ... never now. If you have cached some area and want to use it still, move this cached map to offline "maps" directory (just a suggestion). Anyway I tested it with A2.1. Maybe something changed since that so you can try to keep copy of this file in mapsOnline also and let me and others know, how this works with bigger files on newer system

[xxc]

Ok thanks ! I'll do a "backup" to the offline maps directory and try to keep a copy on mapsOnline.
We'll see

[Jens21]

Hi,
now I have the same problem, I download a Outdoor Active map step by step over a few weeks. Now is my file size over 2GB. Is it possible zu reduce the file size? I don´t want to download the map new.
Why is there no message when the size goes over 2GB?

The file in the online Map directory is working, but this is not a good solution.

Best regards
Jens21

[Menion]

Hi Jens,
  I already read you email. Sorry but I have no idea how to simply remove some part of map from file. It's a basic SQLite database so If I have same problem, I'll download for example extension to firefox (SQLite manager) and manually delete some lines and rows by executing SQL query.

[Jens21]

Hi,
thank you for your answer, I done it, and it works. So far so god.

But now I have a new problem.
I use one SQL File for a complete map of Germany, but only a few zoom levels.
And I had a different SQL file with a map with more zooms level of my home area.
Normally when I select the Germany file, I zoom in the map, Locus change automatically to the other SQL File.
This function doesn´t work since a few days.

[prawns]

Is the 2gig map limit still a issue?

Im new to Locus but have maps I downloaded myself using MOBAC up to 2.7gig in size,  but I have no issues here at all with loading or viewing them so far

The first time I load Locus with a 2gig+ new map copied to /map on my SDcard it took about 40seconds to load up, but after the very first run is done with a new map the loading speed of locus returns to normal (seconds)

Is the 2gig limit a "non issue" now or perhaps I might get issues later?

 So far locus has handled it all beautifully with a few 2+gig maps placed in the same directory /maps/googlehybrid running fine here.  Mind you I had to hack MOBAC 1.9 to get google hybrid maps back in the list and I cant seem to figure out how to get Microsoft Hybrid in the MOBAC list after following instructions

PS the image verification on here is really bad. I cant read it. It wont let me listen to the letters either unless I download the audio file manually - but the audio file sounds the same for alot of letters (B sounds like Z sounds like V sounds like C sounds like E)

Im thinking about half the people give up in frustration trying to post?