Submissions being duplicated with same uuid

Hello @dianedetoeuf,
Could you provide more details, please:

  • At which place do you get/see the duplicates? Table view? Export?
  • Could you try several times, with performant server/internet connection, if you get the same duplicates?
  • In your previous example (Sep 2020) the cases in your screenshot had only same _uuid, but different _id. (Same in screenshot of @Bernard_26). Is this the same today?
  • Are all other data of the cases the same, incl. internal data like full submission_time?
  • What happens if you try to view or edit the duplicates? Did you ever use Briefcase on this data set?
  • Do the cases have (multiple) media attachments?
  • Could someone from the KoBo Core team verify for this project that there are really duplicates in the database (or only in the table view)?

As mentioned above by jnm, there is an open github bug report (since July 2018).

I am afraid _uuid duplication is a crucial issue, meaning that the _uuid cannot be trusted as unique. Different to the existing KoBo and ODK documentation. e.g.
ODK XForms Specification, Random Numbers for Questionnaire ID,
Form Operators and Functions — ODK Docs
https://community.kobotoolbox.org/t/what-are-the-relation-between-these-columns-you-get-while-exporting-data-in-excel/9523/2
“The UUID once received will never be duplicated i.e. i have received a UUID of e45577db-085d-47a0-b1d4-0d9799077b5a for my submission as shown in the image above. No one else in the internet should receive this UUID again.”

There is also another ODK thread on duplicates here:

https://docs.getodk.org/aggregate-data-access/#publishing
“Under certain failure conditions, the downstream service can receive multiple copies of a given submission. This is known, expected, behavior.
Duplicates typically occur if the downstream service is slow to respond or acknowledge a request. It is your responsibility to detect and eliminate these duplicates should they occur (they will always have exactly the same information in all fields).”

See also
https://forum.odk-x.org/t/is-it-possible-to-alert-the-user-of-the-duplicate-records/1054/2:
“If you are using ODK-X to create the identifiers (the uuid) you would never end up with two of the same uuid, so duplication would be avoided.”

Universally unique identifier - Wikipedia “The probability to find a duplicate within 103 trillion version-4 UUIDs is one in a billion.”

cc @jnm and @Xiphware : Any new info on this, please?

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