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Emergency: Help Needed with Data Loss in Table Auto Dedupe Issue

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I sent this issue in as a reply on another thread via email on Saturday, but thought I'd follow up here because it's an emergency and it's inhibiting my ability to move forward with my work today. I have a table that deleted around 3k rows for reasons I cannot discern. Here's the table in question: https://app.clay.com/workspaces/77915/workbooks/wb_0swbkzeigkyochJsEKu/tables/t_0swblkgwAxirmpbtXoA/views/gv_0sxqvhrEc5aSFKFiyjA Table

Originally contained >7,000 rows

What I changed

1.
Email column type changed from Text → Email
2.
Added a Formula column to output all emails in lowercase (as Text)

What happened

Rows began disappearing immediately after step 2
Auto Dedupe was enabled on the Email column
It appears the type conversion alone didn’t trigger deletion—only once the lowercase formula ran did the de-duplication process start removing rows
Thousands of non-duplicate rows were deleted

What I tried to stop it

Deleted the lowercase Formula column
Reverted the Email column back to Text format
Disabled Auto Dedupe
Paused table updates

→ Result: deletions stopped, but ~3,000 rows are already gone What I need

Help understanding why changing column type + adding a formula triggered Auto Dedupe to delete so many non-duplicate rows
Assistance recovering my missing rows (if possible)

I sent a loom in via email in reply to my other support thread on Saturday - DM me if you'd like me to send it here as well. Thanks!

5 comments

Channeled
APP
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Changing the Email column type and adding a lowercase formula likely caused Auto Dedupe to identify more rows as duplicates. Deduplication is case-sensitive and considers exact string matches, including whitespace. When you converted all emails to lowercase, previously distinct entries (e.g., "John@Email.com" and "john@email.com") became identical, triggering Auto Dedupe to delete what it now saw as duplicates—even if they were originally unique due to case differences. Unfortunately, deleted rows from deduplication cannot be recovered. Only entire deleted tables can be restored from the Archive or Trash, not individual rows. If you need further help, you can request human assistance by clicking on "Talk to a person."
Sources: Table columns | Documentation | Clay University Table management settings | Documentation | Clay University Recover Deleted Tables, Permanently Delete Tables Delete content within your workspace | Documentation | Clay University
Cory T.
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To clarify, the row that had auto-deduplication enabled was not the row that was changed to lower case any capital letters in the email column - that was a separate row I had set up that seemed to trigger something within the table that caused rows to start disappearing. Here is the table again: https://app.clay.com/workspaces/77915/workbooks/wb_0swbkzeigkyochJsEKu/tables/t_0swblkgwAxirmpbtXoA/views/gv_0sxqvhrEc5aSFKFiyjA
LuisArturo
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Hey there Cory thanks for reaching out, sorry for the delay here, taking a look at this, can you clarify which column was the one that had the deduped enabled here. Want to check and see how this logic could have come through here.
Cory T.
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Hey LuisArturo thanks for getting back to me. Bo actually replied yesterday via email and said he was going to check the logs on this so not sure if you want to tackle it as well. I am essentially stuck until I find out if it's possible to restore the lost rows though, so if you have any idea on if that's possible, please let me know. The "✅email" column is what had the auto dedupe enabled. I'll DM you the loom I shared with Bo.
LuisArturo
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Ah ok thank you for letting me know, then will merge this ticket with the email one, to avoid any back and forth or mix messages

Emergency: Help Needed with Data Loss in Table Auto Dedupe Issue | Clay