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Enable history tracking (SCD type 2)

Applies to: check marked yes API-based pipeline authoring check marked yes SaaS connectors check marked yes Database connectors

The history tracking setting, also known as the slowly changing dimensions (SCD) setting, determines how to handle changes in your data over time. Turn history tracking off (SCD type 1) to overwrite outdated records as they're updated and deleted in the source. Turn history tracking on (SCD type 2) to maintain a history of those changes. Deleting a table or column in the source does not delete that data from the destination, even when SCD type 1 is selected.

Example: History tracking behavior

For example, let's say that you ingest the following table:

Example source table

Let's also say that Alice's favorite color changes to purple on January 2.

If history tracking is off (SCD type 1), the next run of the ingestion pipeline updates that row in the destination table.

SCD type 1 example

If history tracking is on (SCD type 2), the ingestion pipeline keeps the old row and adds the update as a new row. It marks the old row as inactive so that you know which row is up-to-date.

SCD type 2 example

Not all connectors support SCD type 2. For a list of supported connectors, see Feature compatibility.

Syntax

The scd_type setting supports the following values:

  • SCD_TYPE_1 (history tracking off)
  • SCD_TYPE_2 (history tracking on)

For example, to turn history tracking on, set the following in your pipeline configuration:

YAML
scd_type: SCD_TYPE_2

Google Analytics configuration

SCD type 2 is supported for the users and pseudonymous_users tables using last_updated_date as the cursor column. It's not supported for event-level tables, which are append-only.

By default, history tracking is off (SCD type 1). The following YAML configuration shows how to change this setting in a bundle:

YAML
resources:
pipelines:
pipeline_ga4:
name: <pipeline>
catalog: <destination-catalog>
schema: <destination-schema>
ingestion_definition:
connection_name: <connection>
objects:
- table:
source_url: <project-id>
source_schema: <property-name>
destination_catalog: <destination-catalog>
destination_schema: <destination-schema>
table_configuration:
scd_type: SCD_TYPE_2

Salesforce configuration

By default, history tracking is off (SCD type 1). The following YAML configuration shows how to change this setting in a bundle:

YAML
resources:
pipelines:
pipeline_sfdc:
name: <pipeline>
catalog: <destination-catalog>
schema: <destination-schema>
ingestion_definition:
connection_name: <connection>
objects:
- table:
source_schema: <source-schema>
source_table: <source-table>
destination_catalog: <destination-catalog>
destination_schema: <destination-schema>
table_configuration:
scd_type: SCD_TYPE_2

SQL Server configuration

The sequence column that you specify in the pipeline configuration (for example, last_updated, modified_at, or version_number) determines the time span that each row version was active (recorded in the __START_AT and __END_AT columns in the target table).

The following sequence_by column types are supported:

  • Timestamp
  • Date
  • Integer
  • Long
  • String

By default, history tracking is off (SCD type 1). The following YAML configuration shows how to change this setting in a bundle:

YAML
resources:
pipelines:
pipeline_sqlserver:
name: <pipeline>
catalog: <destination-catalog>
schema: <destination-schema>
ingestion_definition:
connection_name: <connection>
objects:
- table:
source_catalog: <source-catalog>
source_schema: <source-schema>
source_table: <source-table>
destination_catalog: <destination-catalog>
destination_schema: <destination-schema>
table_configuration:
scd_type: SCD_TYPE_2
sequence_by: <sequence-column>

Workday configuration

By default, history tracking is off (SCD type 1). The following YAML configuration shows how to change this setting in a bundle:

YAML
resources:
pipelines:
pipeline_workday:
name: <pipeline>
catalog: <destination-catalog>
schema: <destination-schema>
ingestion_definition:
connection_name: <connection>
objects:
- report:
source_url: <report-url>
destination_catalog: <destination-catalog>
destination_schema: <destination-schema>
table_configuration:
scd_type: SCD_TYPE_2

Limitations

Running a full refresh replaces the entire table. This removes all previous row versions. New history is tracked starting from the refresh point.