Import fails with "'idx_records_matched_id_gen', duplicate key value violates unique constraint" SRS logs JUNIPER HF

Documents Case 3 in the comments on MODINVSTOR-815

This issue is observed in a Honeysuckle HF3 environment and in Iris, but may have been fixed by Hotfix 1

Additional info from one of cappadona's comments below:

1. Data Import Run A: Create 10,300 SRS MARC Bib and Instances using new Data Import default job profile for Iris (cu_initial-create_10300recs.mrc)
2. Retrieve Instance UUIDs via SRS MARC Query API:
   { "fieldsSearchExpression": "948.d ^= 'cu-batch'" }
3. Export the full MARC for the 10,300 records using Data Export default job profile
4. Create & associate DI profiles
   • job profile – moddataimp419_job.json
   • match profile (001 -> instance hrid) – moddataimp419_match.json
   • action profile (UPDATE Instance on match) – moddataimp419_action.json
   • mapping (overlay) – moddataimp419_mapping.json
5. Process the exported MARC (cleanup OCLC identifiers in 035$a)
   Note: When we originally ran this and encountered the error, we  DID NOT strip the 999 ff
6. Data Import Run B: Update the SRS MARC Bib records using job profile from #4 (1 file: 10,300 records)

I decided to try running through the test on the Iris reference environment and was unsuccessful in making it through all steps. Here are the results:

1. DI Run A: Initial create of 10,300 SRS MARC Bib and Instances (hrid: 17): 12 m
2. Retrieve Instance UUIDs via SRS MARC Query API: 629 ms { "fieldsSearchExpression": "948.d ^= 'cu-batch'" }
3. Export the full MARC for the 10,300 records (hrid: 8): 3 m
4. DI profiles ported via API and manually linked/related
5. Process the exported MARC (cleanup OCLC identifiers in 035$a AND strip 999 ff) with external script: 4 s
6. DI Run B: Update the 10,300 SRS MARC Bib records: Stuck at 37% after ~10 m

A follow up to SRS MARC Query API reveals 6,471 of the records remain in their original state, so we can conclude that 3,829 were updated (37%)

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When attempting to import a file - the import fails and the following message is observed in mod-source-record-storage logs
"idx_records_matched_id_gen", duplicate key value violates unique constraint

New Import's which fail are attempts to update records from a previous Data Import for a batch of appox 14K that also had issues (specifically the earlier batch failed with – Completed with errors status.)

Need analysis to understand state of related db table entries for Data Import attempts which are failing with this constraint error