[jp] Unable to transfer memo database

  • Previous message: [jp] Unable to transfer memo database
  • David A. Desrosiers desrod at gnu-designs.com
    Sat Jan 26 22:09:41 EST 2008

     

    On Sat, 2008-01-26 at 17:35 -0500, Rick Lapp wrote:
    > I can usually get it to complete after doing a 
    > hard reset on the Palm but not always. 
    
    I bet a soft-reset would solve it too. 
    
    Since the TX is running OS5, a soft reset would cause the device to copy
    ALL records from the Memos database (MemosDB-PMem.pdb) to the "Classic"
    version used by the MemoPad application (MemoDB.pdb), which J-Pilot can
    then read natively without any problems. 
    
    iirc, J-Pilot can also read the new Memos application storage without
    any problems as well. 
    
    Obviously a hard-reset starts the slate clean with the same situation.
    
    > I've tried deleting / cleaning old records trying to keep the sizes
    > down, deleting some content from individual records keeping their size
    > down but have not found the 'smoking gun' that is the root cause of
    > the problem.
    
    Keep in mind that MemoPad (the OS4 and earlier application that stored
    its records in MemoDB.pdb) is a "legacy" application, and its records
    were limited to a 4,096 bytes (4k) apiece if you wanted to retain the
    ability to edit them. 
    
    If you wanted them to be "read-only" entries, you can create them up to
    65,490 bytes in size, but you can't edit them after you sync them to the
    device. 
    
    The new Memos application (which stores its data in MemosDB-PMem.pdb) is
    an "Extended" database application, and those per-record limits no
    longer exist. 
    
    If (and this is just a guess), you have records with > 65k in them
    coming from Memos as well as records which are < 4k, J-Pilot (and the
    MemoPad database) may be getting confused when it tries to consolidate
    those into one consistent "view" of the memos on your device. 
    
    What really happens under the hood when Memos tries to copy 72k of data
    sitting in a (valid) Memos record to a MemoPad record which can't take
    more than 65k of data? Does it truncate it? Ignore it? Skip it? Does it
    tell MemoPad that it has 72k of data and only sends 4k? 
    
    I've personally never gone and tested it in great detail, but if
    MemoPad's database has pointers past where the actual end of the record
    is supposed to be, things can get very ugly fast.
    
    
    -- 
    David A. Desrosiers
    desrod at gnu-designs.com
    Skype...: 860-967-3820
    
    
    

     

     

    More information about the jpilot mailing list