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  • 1.  Tables in in dropbox freezing randomly Mapinfo 15.0.2

    Posted 01-13-2023 12:52
    Edited by Mary Wilks 01-13-2023 12:52
    My tables are in dropbox but local (not in the cloud other than syncing periodically). I experience random freezing of mapinfo to where I have to close the program and restart to continue editing a table. It also sometimes says when I hit save save 'Cannot access file xyz.dat for writing. Please be sure that this file is not open in another application (retry/cancel). This happens mostly when I am doing extensive splitting of polygons and deleting polylines used to split. 

    Has anyone experienced this and know why this happens or what can be done to avoid? Thank you

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    Mary Wilks
    CAROLINA PRECISION CONSULTING
    Rocky Mount NC
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  • 2.  RE: Tables in in dropbox freezing randomly Mapinfo 15.0.2

    Posted 01-14-2023 01:37
    Edited by John Hollingsworth 01-15-2023 14:42

    Hi Mary,

    As someone who manages a 75-user footprint with all of our data stored in Dropbox, I hope I can help.

    The Dropbox client has to periodically scan each file under its purview for changes and to do so has to put a momentary lock on the files. When editing and/or saving a MapInfo file, the current state of that file is in flux and sometimes Dropbox sneaks in and locks it and MapInfo does not like that.

    This is why you experience this error during compute-intensive operations. MapInfo is using temp files in the background and Dropbox sees those as fair game for locking even though they are going to be cleaned up at the end of the operation anyway.

    Potential Solutions:

    1 - Pause Dropbox before you do a very complex operation. Run the tool or operation and when it is done, unpause Dropbox.
      Pros: Fixes the issue
      Cons: The time it takes for the Dropbox client to start up is directly proportional to the number of files being actively synced in Dropbox. So there is a potential time cost for restarting the client depending on your situation.

    2 - If the tool you are running is one you wrote in MapBasic, call the wait(n) command (code shown below) right after you use the Commit Table. This will give Dropbox time to lock the file, sync the changes, and release the file. Usually, a parameter of one second will do the trick, but I've coded more in some situations.

    Sub Wait(ByVal secs As Integer)
    Dim i As Integer
    i = Timer()
    Do Until Timer() >= i + secs Loop
    End Sub

    Pros: Mostly fixes the problem
    Cons: - Doesn't avoid conflicts with the temp files that MapInfo creates on its own
               - You have to refactor a bunch of code in a bunch of places


    Good luck!



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    John Hollingsworth
    GIS Director
    Clear Channel Outdoor
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  • 3.  RE: Tables in in dropbox freezing randomly Mapinfo 15.0.2

    Posted 01-14-2023 17:06
    John, thank you. I have 'paused' my dropbox and told it not to sync til tomorrow. I went to work and it froze again after 15 mins or so of work. Do you have any other ideas what could be causing the freeze up? Maybe its unrelated to dropbox.

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    Mary Wilks
    CAROLINA PRECISION CONSULTING
    Rocky Mount NC
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  • 4.  RE: Tables in in dropbox freezing randomly Mapinfo 15.0.2

    Posted 01-15-2023 14:41

    Dropbox can take a long time to restart so this might just be how it is.

    A potential help can be reducing the number of files that the client has to manage by using the Selective Sync feature (under Preferences->Sync->Select Folders in the client). This can dramatically reduce the time that the client needs to start up.

    Another option I forgot earlier is that if you are running a tool that you developed in Mapbasic, is to write the code such that it saves a working table to the user's temporary folder (you can get this in Mapbasic using PathToDirectory$(TempFileName$("")). Do any further processing on that table and then the last step is to save it into the destination Dropbox folder.



    ------------------------------
    John Hollingsworth
    GIS Director
    Clear Channel Outdoor
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  • 5.  RE: Tables in in dropbox freezing randomly Mapinfo 15.0.2

    Posted 01-14-2023 02:52
    The obvious solution is to move the file out of the dropbox folder, do the edits and then move it back again. I assume no one else is trying to edit it at the same time.

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    Uffe Kousgaard
    ROUTEWARE
    Roskilde
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