Changes between Version 14 and Version 15 of DataStorageEN


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Timestamp:
Jul 23, 2011, 7:46:41 PM (9 years ago)
Author:
Martin Kolman
Comment:

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  • DataStorageEN

    v14 v15  
    1717
    1818'''What is this good for ?'''[[br]]
    19 As mentioned earlier in this thread and also in a related Mappero thread, tile take up more space than expected because each tile, even if only 500B in size, takes a whole 64kB cluster.
     19As 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.
    2020When using sqlite for tile storage, there are basically just 2 files per layer, not the usual tens of thousands of files and folders.
    2121
     
    2424
    2525'''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 ! :)
     26It 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 ! :)
    2727
    2828'''What about the 4GB maximum file size limit on FAT32 ?'''[[br]]
     
    3030
    3131'''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 an 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:
     32The 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:
    3333{{{
    3434store.sqlite.0
     
    4545Both 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.
    4646
    47 These database files are stored in the
    48 corresponding layer folders.
     47Database files are stored in the corresponding layer folders.
    4948
    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.
     49When 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.
    5150
    5251'''Could this be used by other navigation apps ?'''[[br]]
    53 Why do you think I just roughly described how it works ? :D
     52Why do you think I just described how it works ? :D
    5453
    5554== POI ==