[Solved] Given this merge config:merge: unique_key: ['user_id']The merge is not updating existing rows as expected. What could be wrong? | dbt

dbt - Incremental Models

Given this merge config:

merge:
  unique_key: ['user_id']

The merge is not updating existing rows as expected. What could be wrong?

AThe target table is empty, so no rows to update

BThe merge config requires a single string, not a list

CThe merge operation requires a separate update clause

DThe unique_key column 'user_id' does not uniquely identify rows in source or target

Step-by-Step Solution

Solution:

Step 1: Understand update behavior
If unique_key does not uniquely identify rows, merge cannot match and update existing rows.
Step 2: Check other options
List syntax is valid, update clause is implicit, and target emptiness would not cause no updates but inserts.
Final Answer:
The unique_key column 'user_id' does not uniquely identify rows in source or target -> Option D
Quick Check:
Non-unique keys prevent updates in merge [OK]

Quick Trick: Ensure unique_key uniquely identifies rows to update correctly [OK]

Common Mistakes:

MISTAKES

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