# DBT Snapshot has restarted and now has no dbt\_valid\_to NOT NULL rows.

**URL:** <https://discourse.getdbt.com/t/dbt-snapshot-has-restarted-and-now-has-no-dbt-valid-to-not-null-rows/16695>\
**Category:** Help\
**Tags:** snapshots\
**Created:** [October 23, 2024, 9:42am UTC](https://discourse.getdbt.com/t/dbt-snapshot-has-restarted-and-now-has-no-dbt-valid-to-not-null-rows/16695 "2024-10-23T09:42:22Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![immediate\_jon](https://avatars.discourse-cdn.com/v4/letter/i/a9adbd/32.png) [@immediate\_jon](https://discourse.getdbt.com/u/immediate_jon)\
**Post date:** [October 23, 2024, 9:42am UTC](https://discourse.getdbt.com/t/dbt-snapshot-has-restarted-and-now-has-no-dbt-valid-to-not-null-rows/16695/1 "2024-10-23T09:42:22Z")

</div>

## The problem I’m having ------------------------------------------------------------------------------------------

I had a snapshot that worked, using the check strategy to pick up if anyone changes their email address with us. Code:

{% snapshot dev\_dsb\_\_customer\_email\_change\_snapshot\_final %}

```
{{
    config(
        target_schema="snapshots",
        strategy="check",
        unique_key="hash_id",
        check_cols=["person_reference_urn", "email_address"],
    )
}}
select
    convert(varchar(32), hashbytes('MD5', person_reference_urn), 2) as hash_id,
    *
from
    (
        select
            row_number() over (
                partition by person_reference_urn
                order by concat(email_address, phone_number) desc
            ) as rowss,
            *
        from {{ source("dev_dsb", "customer") }}
    ) as a
where rowss = 1

```

{% endsnapshot %}

## What I’ve already tried --------------------------------------------------------------------------

To be honest we haven’t tried much, we just came in today and the snapshot had no dates in the dbt\_valid\_to column, where there used to be about a 1000. We have re-run and checked adn the same issue persists.

## Full question --------------------------------------------------------------------------

I am more than happy to accept this is something we did, however is there a scenario where the snapshot will be restarted when run or built?

Help is appreciated.