hard_deletes
Available from dbt v1.9 or with Versionless dbt Cloud.
snapshots:
- name: <snapshot_name>
config:
hard_deletes: 'ignore' | 'invalidate' | 'new_record'
snapshots:
<resource-path>:
+hard_deletes: "ignore" | "invalidate" | "new_record"
{{
config(
unique_key='id',
strategy='timestamp',
updated_at='updated_at',
hard_deletes='ignore' | 'invalidate' | 'new_record'
)
}}
Description
The hard_deletes
config gives you more control on how to handle deleted rows from the source. Supported options are ignore
(default), invalidate
(replaces the legacy invalidate_hard_deletes=true
), and new_record
. Note that new_record
will create a new metadata column in the snapshot table.
If you're updating an existing snapshot to use the hard_deletes
config, dbt will not handle migrations automatically. We recommend either only using these settings for net-new snapshots, or arranging an update of pre-existing tables before enabling this setting.
Default
By default, if you don’t specify hard_deletes
, it'll automatically default to ignore
. Deleted rows will not be tracked and their dbt_valid_to
column remains NULL
.
The hard_deletes
config has three methods:
Methods | Description |
---|---|
ignore (default) | No action for deleted records. |
invalidate | Behaves the same as the existing invalidate_hard_deletes=true , where deleted records are invalidated by setting dbt_valid_to to current time. This method replaces the invalidate_hard_deletes config to give you more control on how to handle deleted rows from the source. |
new_record | Tracks deleted records as new rows using the dbt_is_deleted meta field when records are deleted. |
Considerations
- Backward compatibility: The
invalidate_hard_deletes
config is still supported for existing snapshots but can't be used alongsidehard_deletes
. - New snapshots: For new snapshots, we recommend using
hard_deletes
instead ofinvalidate_hard_deletes
. - Migration: If you switch an existing snapshot to use
hard_deletes
without migrating your data, you may encounter inconsistent or incorrect results, such as a mix of old and new data formats.
Example
snapshots:
- name: my_snapshot
config:
hard_deletes: new_record # options are: 'ignore', 'invalidate', or 'new_record'
strategy: timestamp
updated_at: updated_at
columns:
- name: dbt_valid_from
description: Timestamp when the record became valid.
- name: dbt_valid_to
description: Timestamp when the record stopped being valid.
- name: dbt_is_deleted
description: Indicates whether the record was deleted.
The resulting snapshot table contains the hard_deletes: new_record
configuration. If a record is deleted and later restored, the resulting snapshot table might look like this:
id | dbt_scd_id | Status | dbt_updated_at | dbt_valid_from | dbt_valid_to | dbt_is_deleted |
---|---|---|---|---|---|---|
1 | 60a1f1dbdf899a4dd... | pending | 2024-10-02 ... | 2024-05-19... | 2024-05-20 ... | False |
1 | b1885d098f8bcff51... | pending | 2024-10-02 ... | 2024-05-20 ... | 2024-06-03 ... | True |
1 | b1885d098f8bcff53... | shipped | 2024-10-02 ... | 2024-06-03 ... | False | |
2 | b1885d098f8bcff55... | active | 2024-10-02 ... | 2024-05-19 ... | False |
In this example, the dbt_is_deleted
column is set to True
when the record is deleted. When the record is restored, the dbt_is_deleted
column is set to False
.