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Is GUID global unique? RRS feed

  • Question

  • Greetings,

    if i create a MS-Project client file and I add a task, I can view a uniqueID. This uniqueID is only unique in the project file.

    I want a uniqueID by a task that is - with a high probability - global unique.

    I found the field GUID (with this content e.g. B526E49A-CD40-E511-BAFC-97BA30AC79BC)

    Is the GUID "gloabal" unique?

    Thank you!

        Michael

    Wednesday, August 12, 2015 8:54 AM

Answers

  • We had a discussion with Microsoft a while ago about this topic. Here is what was said.

    In Project 2010, for example, it was purely random. In 2013 a random seed GUID is chosen for the first element and after that it’s more sequential. More precisely in 2007 and 2010 Project just generates new GUIDs probably using the .NET Guid.NewGuid() method – which are random.


    Hope this helps,


    Guillaume Rouyre, MBA, MVP, P-Seller |

    • Marked as answer by Michael-Markus Wednesday, August 12, 2015 10:38 AM
    Wednesday, August 12, 2015 10:20 AM
    Moderator

All replies

  • Hi Michael,

    Indeed the GUID is a unique task identifier at server level.


    Hope this helps,


    Guillaume Rouyre, MBA, MVP, P-Seller |

    Wednesday, August 12, 2015 9:05 AM
    Moderator
  • > Indeed the GUID is a unique task identifier at server level.

    Which does "server level" mean?

    I have no project server, I have only MS-Project Client.

    Regards

       Michael

    Wednesday, August 12, 2015 9:19 AM
  • Sorry, I though you have Project Server because you posted your question in the Project Server forum.

    Anyway, my reply also applied to MS Project client without Project Server. The task GUID is the unique identifier.


    Hope this helps,


    Guillaume Rouyre, MBA, MVP, P-Seller |

    Wednesday, August 12, 2015 9:38 AM
    Moderator
  • Thank you!

    > The task GUID is the unique identifier.

    all around the world?

    Wednesday, August 12, 2015 9:50 AM
  • Good question... Obviously not around the world since your desktop application cannot know the GUID of another desktop application, but I would say unique on your machine.

    Hope this helps,


    Guillaume Rouyre, MBA, MVP, P-Seller |

    Wednesday, August 12, 2015 9:54 AM
    Moderator
  • I have a individual project database, there get the task from many ms-project files from many machines.

    > cannot know the GUID of another desktop application

    Correct, but with random algorithm it is possible to reach 99,9% probability of "all around the world" unique ID

    Is perhaps described somewhere, what criteria the GUID is generated?

    Regards   Michael

    Wednesday, August 12, 2015 10:08 AM
  • We had a discussion with Microsoft a while ago about this topic. Here is what was said.

    In Project 2010, for example, it was purely random. In 2013 a random seed GUID is chosen for the first element and after that it’s more sequential. More precisely in 2007 and 2010 Project just generates new GUIDs probably using the .NET Guid.NewGuid() method – which are random.


    Hope this helps,


    Guillaume Rouyre, MBA, MVP, P-Seller |

    • Marked as answer by Michael-Markus Wednesday, August 12, 2015 10:38 AM
    Wednesday, August 12, 2015 10:20 AM
    Moderator
  • Thank you!
    Wednesday, August 12, 2015 10:38 AM