What will be the effect of running this dbt incremental model for the second time?

medium📝 Predict Output Q4 of 15

dbt - Incremental Models

{{ config(materialized='incremental') }}
select * from source_table where updated_at > (select max(updated_at) from {{ this }})

AAll rows from source_table will be reprocessed and replaced

BOnly new rows with updated_at greater than the last max updated_at in the model will be appended

CThe model will fail due to a syntax error in the where clause

DThe model will delete all existing rows before inserting new data

Step-by-Step Solution

Solution:

Step 1: Understand incremental logic
The model filters source_table rows where updated_at is greater than the max updated_at already in the model.
Step 2: Effect on second run
On the second run, only rows with updated_at newer than the last max updated_at will be appended, avoiding full reload.
Final Answer:
Only new rows with updated_at greater than the last max updated_at in the model will be appended -> Option B
Quick Check:
Incremental models append new data based on max timestamp [OK]

Quick Trick: Incremental models append only newer data [OK]

Common Mistakes:

MISTAKES

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