[Bug] relation "<model>__dbt_tmp" already exists errors appearing

[tobiascadee]

Is this a new bug in dbt-core?

• I believe this is a new bug in dbt-core
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

When running models with table materialisation, this error will come up irregularly:
relation "<model>__dbt_tmp" already exists
I have already tried using a pre hook to drop the tmp tables if they exist but it does not work.

Expected Behavior

Model to just run

Steps To Reproduce

1. dbt project possible relevant config:

models:
  data_transformations:
    +on_schema_change: "sync_all_columns"
    +bind: false
    +incremental_strategy: "merge"

    staging:
      +materialized: view
      +schema: staging

Relevant log output

12:10:38  2 of 20 ERROR creating sql incremental model dbt_tobias.stg_ios__identities .... [ERROR in 43.83s]
12:11:04    Database Error in model stg_ios__identities (models/staging/ios/stg_ios__identities.sql)
  relation "stg_ios__identities__dbt_tmp" already exists
  compiled code at target/run/data_transformations/models/staging/ios/stg_ios__identities.sql

Environment

- OS: macOS Tahoe 26.1
- Python: 3.11.11
- dbt-core: 1.9.10
- dbt-redshift: 1.9.5

Which database adapter are you using with dbt?

redshift

Additional Context

No response

[avwoodmark]

Hi there,
we running into the same problem. Models which exists for over two years started to fail with "relation "stg_ios__identities__dbt_tmp" already exists". Starting on at 18.10.2025.
We running batch jobs to run dbt commands on AWS Redshift.

First with environment:

- Python: 3.9.11
- dbt-core: 1.8.1
- dbt-redshift: 1.8.1

We updated dbt to:

- Python: 3.9.11
- dbt-core: 1.10.13
- dbt-redshift: 1.9.5

Error no longer occurs daily but has not been resolved.

[tobiascadee]

Sounds exactly like our problem! we still have the issue daily but just very irregular.

[paul-cunningham-jt]

+1 here, we're also seeing the same problem since November 14th, also irregular.
Engaged with both AWS and dbt Cloud support. I'll feedback here if I find anything out

[shiv-io]

+1 also running into this somewhat unpredictably but frequently (1-3 times a week) over the last few weeks!

- Python: 3.13.7
- dbt-core: 1.10.11
- dbt-redshift: 1.9.5

[shiv-io]

I have already tried using a pre hook to drop the tmp tables if they exist but it does not work.

@tobiascadee, do you mean that this issue continued to occur even after implementing the pre-hook workaround you described?

[Simarglok]

The same issue. Our config:

{{
    config(
        materialized='table',
        sort='day',
        dist='even',
    )
}}

Running with dbt=1.10.13
Registered adapter: redshift=1.9.5
Python 3.12

[tobiascadee]

@shiv-io correct, it seems to be originating in a part of the run process where we don't have control

[paul-cunningham-jt]

AWS support were able to resolve these symptoms for us.
Their last message in our support ticket said:

Thank you for your patience and co-operation while I was working with internal team on this issue.
We have detected a failure for CTAS operations on your Amazon Redshift cluster '' in AWS region which was caused due to an internal configuration related error. Our internal team has applied the necessary changes to fix the issue and rebooted the cluster to get configuration changes effective. Please validate and let us know if the issue still persist.
We regret for the inconvenience caused. Please let us know if you have any questions or concerns.

[shiv-io]

@paul-cunningham-jt Thanks for the update! Any chance you're open to sharing your AWS case number? I am in touch with AWS Support and it would help to reference your case number!

[paul-cunningham-jt]

Hi @shiv-io

@paul-cunningham-jt Thanks for the update! Any chance you're open to sharing your AWS case number? I am in touch with AWS Support and it would help to reference your case number!

Here you are:

Case details
Subject
DBT random failures
Case ID
176423840700109
Created
2025-11-27T10:13:27.476Z

[shiv-io]

Thanks, @paul-cunningham-jt!