[Solved] A dbt incremental model uses this filter:WHERE updated_at > (SELECT MAX(updated_at) FROM {{ this }})but no new rows are added after source updates. What is the most probable reason? | dbt

dbt - Performance Optimization

A dbt incremental model uses this filter:

WHERE updated_at > (SELECT MAX(updated_at) FROM {{ this }})

but no new rows are added after source updates. What is the most probable reason?

AThe model is materialized as a view instead of incremental.

BThe model is missing the <code>unique_key</code> configuration.

CThe <code>updated_at</code> column in the source is not properly updated or has no newer values.

DThe dbt version does not support incremental models.

Step-by-Step Solution

Solution:

Step 1: Understand the filter logic
The incremental filter selects rows where updated_at is greater than the max updated_at in the existing table.
Step 2: Check source data freshness
If no new rows appear, it likely means the source's updated_at values are not newer than the max in the target table.
Step 3: Other options
Missing unique_key causes merge issues but not no rows; materialization as view disables incremental; dbt supports incremental for many versions.
Final Answer:
The source's updated_at column has no newer values -> Option C
Quick Check:
New rows require newer updated_at values [OK]

Quick Trick: No new rows if source timestamps aren't newer than target [OK]

Common Mistakes:

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