Photometry deduplication logic does not exclude record being updated when checking against existing records

[acrellin]

A PATCH or PUT request can lead to a duplication error b/c the new data will be checked against the corresponding existing record, leading to an error if none of the values in the deduplication index are being changed.

[dannygoldstein]

Yes this is not good, we should allow PK mutations. Currently our order of ops is: 1. Check for duplicates. 2. Mutate. 3. Commit.

Perhaps we can fix this by simply reversing the above? I.e., 1. Mutate 2. Check for duplicates, 3. Commit?

[mcoughlin]

@profjsb @guynir42 Do we know understand this well enough to make it actionable?

[guynir42]

I think I know what they are talking about.