Reference checks
Last modified on 10-Jul-24
Use a reference check to validate that column contents match between datasets in the same data source.
See also: Compare data using SodaCL
checks for dim_department_group:
- values in (department_group_name) must exist in dim_employee (department_name)
- values in (birthdate) must not exist in dim_department_group_prod (birthdate)
✖️ Requires Soda Core Scientific (included in a Soda Agent)
✔️ Supported in Soda Core
✔️ Supported in Soda Library + Soda Cloud
✔️ Supported in Soda Cloud Agreements + Soda Agent
✖️ Available as a no-code check
Define reference checks
Failed row samples
Optional check configurations
Go further
Define reference checks
In the context of SodaCL check types, reference checks are unique. This check is limited in its syntax variation, with only a few mutable parts to specify column and dataset names.
The example below checks that the values in the source column, department_group_name
, in the dim_department_group
dataset exist somewhere in the destination column, department_name
, in the dim_employee
dataset. If the values are absent in the department_name
column, the check fails.
- Soda CL considers missing values in the source column as invalid.
- Optionally, do not use brackets around column names. The brackets serve as visual aids to improve check readability.
checks for dim_department_group:
- values in (department_group_name) must exist in dim_employee (department_name)
You can also validate that data in one dataset does not exist in another.
checks for dim_customer_staging:
- values in (birthdate) must not exist in dim_customer_prod (birthdate)
Reference checks and dataframes
If you are using reference checks with a Spark or Databricks data source to validate the existence of values in two datasets within the same schema, you must first convert your DataFrames into temp views to add them to the Spark session, as in the following example.
# after adding your Spark session to the scan
df.createOrReplaceTempView("df")
df2.createOrReplaceTempView("df2")
Failed row samples
Reference checks automatically collect samples of any failed rows to display Soda Cloud. The default number of failed row samples that Soda collects and displays is 100.
If you wish to limit or broaden the sample size, you can use the samples limit
configuration in a reference check configuration. You can add this configuration to your checks YAML file for Soda Library, or when writing checks as part of an agreement in Soda Cloud.
checks for dim_customers:
- values in (state_code, state_name) must exist in iso_3166-2 (code, subdivision_name):
samples limit: 20
For security, you can add a configuration to your data source connection details to prevent Soda from collecting failed rows samples from specific columns that contain sensitive data. Refer to Disable failed rows sampling for specific columns.
Alternatively, you can set the samples limit
to 0
to prevent Soda from collecting and sending failed rows samples for an individual check, as in the following example.
checks for dim_customers:
- values in (state_code, state_name) must exist in iso_3166-2 (code, subdivision_name):
samples limit: 0
You can also use a samples columns
configuration to a check to specify the columns for which Soda must implicitly collect failed row sample values, as in the following example. Soda only collects this check’s failed row samples for the columns you specify in the list.
Note that the comma-separated list of samples columns does not support wildcard characters (%).
checks for dim_customers:
- values in (state_code, state_name) must exist in iso_3166-2 (code, subdivision_name):
samples columns: [state_code]
To review the failed rows in Soda Cloud, navigate to the Checks dashboard, then click the row for a reference check. Examine failed rows in the Failed rows tab; see Examine failed row samples for further details.
Optional check configurations
Supported | Configuration | Documentation |
---|---|---|
✓ | Define a name for a reference check; see example. | Customize check names |
✓ | Add an identity to a check. | Add a check identity |
Define alert configurations to specify warn and fail alert conditions. | - | |
Apply an in-check filter to return results for a specific portion of the data in your dataset. | - | |
✓ | Use quotes when identifying dataset or column names; see example. Note that the type of quotes you use must match that which your data source uses. For example, BigQuery uses a backtick (`) as a quotation mark. | Use quotes in a check |
Use wildcard characters ( % or * ) in values in the check. | - | |
Use for each to apply reference checks to multiple datasets in one scan. | - | |
✓ | Apply a dataset filter to partition data during a scan; see example. If you encounter difficulties, see Filter not passed with reference check. | Scan a portion of your dataset |
Example with check name
checks for dim_department_group:
- values in (department_group_name) must exist in dim_employee (department_name):
name: Compare department datasets
Example with quotes
checks for dim_department_group:
- values in ("department_group_name") must exist in dim_employee ("department_name")
Example with dataset filter
Refer to Troubleshoot SodaCL to address challenges specific to reference checks with dataset filters.
filter customers_c8d90f60 [daily]:
where: ts > TIMESTAMP '${NOW}' - interval '100y'
checks for customers_c8d90f60 [daily]:
- values in (cat) must exist in customers_europe (cat2)
Go further
- Problems with reference checks and dataset filters? Refer to Troubleshoot SodaCL.
- Learn more about SodaCL metrics and checks in general.
- Learn more about comparing data using SodaCL.
- Use a schema check to discover missing or forbidden columns in a dataset.
- Need help? Join the Soda community on Slack.
- Reference tips and best practices for SodaCL.
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Documentation always applies to the latest version of Soda products
Last modified on 10-Jul-24