Changes between Version 14 and Version 15 of DataStorageEN
- Timestamp:
- Jul 23, 2011, 7:46:41 PM (13 years ago)
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DataStorageEN
v14 v15 17 17 18 18 '''What is this good for ?'''[[br]] 19 As mentioned earlier in th is thread and also in a related Mappero thread, tiletake up more space than expected because each tile, even if only 500B in size, takes a whole 64kB cluster.19 As mentioned earlier in the modRana thread on talk.maemo.org and also in a related Mappero thread, tiles take up more space than expected because each tile, even if only 500B in size, takes a whole 64kB cluster. 20 20 When using sqlite for tile storage, there are basically just 2 files per layer, not the usual tens of thousands of files and folders. 21 21 … … 24 24 25 25 '''Is it stable ?'''[[br]] 26 It seems to work OK for both normal automatic tile download (including overlay) and batch download. But some errors can still can show up, so please report any unusual behavior when using this ! :)26 It seems to work OK for both normal automatic tile download (including overlay) and batch download. But some errors can still can show up, so please report any unusual behavior, thanks ! :) 27 27 28 28 '''What about the 4GB maximum file size limit on FAT32 ?'''[[br]] … … 30 30 31 31 '''How does it work ?'''[[br]] 32 The tiles are stored in a sqlite database as blobs. There are two types of database files, ''lookup.sqlite'' and ''store.sqlite''. The lookup file stores a ndatabase that indicates in which store the requested tile is. The store file has the actual data. Multiple stores should be numbered in ascending order, starting from 0:32 The tiles are stored in a sqlite database as blobs. There are two types of database files, ''lookup.sqlite'' and ''store.sqlite''. The lookup file stores a database that indicates in which store the requested tile is. The store file has the actual data. Multiple stores should be numbered in ascending order, starting from 0: 33 33 {{{ 34 34 store.sqlite.0 … … 45 45 Both also have a table called version which has an integer column called v. There is a single 1 inserted, which indicates the current version of the table. 46 46 47 These database files are stored in the 48 corresponding layer folders. 47 Database files are stored in the corresponding layer folders. 49 48 50 When looking for a tile in the database, modRana first asks the lookup database and when it gets an answer, it asks the store described in the store_filename for the given coordinates.49 When looking for a tile in the database, modRana first asks the lookup database and when it gets an answer, it asks the store described in the store_filename for the given tile coordinates. 51 50 52 51 '''Could this be used by other navigation apps ?'''[[br]] 53 Why do you think I just roughlydescribed how it works ? :D52 Why do you think I just described how it works ? :D 54 53 55 54 == POI ==