A Validation Result Store is a connector to store and retrieve information about objects generated when data is Validated against an Expectation Suite.
Validation Result Stores allow you to store and retrieve Validation ResultsGenerated when data is Validated against an Expectation or Expectation Suite. that have been generated by CheckpointsThe primary means for validating data in a production deployment of Great Expectations.. These Stores can be accessed and configured through the Data ContextThe primary entry point for a Great Expectations deployment, with configurations and methods for all supporting components., but entries are added to them automatically when a Checkpoint with the appropriate ActionA Python class with a run method that takes a Validation Result and does something with it in its
action_list completes running. A configured Validation Result Store is required in order to work with Great Expectations. A local configuration for a Validation Result Store will be added automatically to
great_expectations.yml when you initialize your Data Context for the first time.
Validation Result Stores ensure that Validation Results are accessible via the Data Context for review and rendering into Data DocsHuman readable documentation generated from Great Expectations metadata detailing Expectations, Validation Results, etc.. Generally speaking, while working with Great Expectations to ValidateThe act of applying an Expectation Suite to a Batch. data you will not need to interact with a Validation Result Store directly outside configuring the StoreA connector to store and retrieve information about metadata in Great Expectations. or configuring Evaluation ParametersA dynamic value used during Validation of an Expectation which is populated by evaluating simple expressions or by referencing previously generated metrics. that reference MetricsA computed attribute of data such as the mean of a column. which can be found in a stored Validation Result. Instead, your Data Context will use your Validation Result Store behind the scenes when Validation Results are retrieved or stored.
Relationship to other objects
Validation Result Stores can be used to store and retrieve Validation Results and associated metadata. The process of storing this information is typically executed by an Action in a Checkpoint's
action_list. Metrics found in the Validation Results stored in Validation Result Stores can also be accessed as Evaluation Parameters when defining Expectations.
When you initialize your Data Context for the first time, a configuration for a local Validation Result Store will automatically be added to
great_expectations.yml. You may change this configuration to work with different environments.
- For more information on configuring a Validation Results Store for a specific environment, see in-depth guides on Validation Result Store configurations.
When interactively creating Expectations that rely on Evaluation Parameters, it is possible to use existing Validation Results that have stored Metrics to populate those parameters. If these Validation Results are not available in memory, then the only way to access them is by retrieving them through a Validation Result Store (if they were stored previously).
When validating Data with a Checkpoint, Validation Results will be stored by the
StoreValidationResultAction if it exists in the Checkpoint's
action_list. This will use a Validation Result Store to store the Validation Result and associated metadata. Some Expectations may also use Evaluation Parameters which are configured to pull Metrics from Validation Results that are available through the Validation Result Store.
You will not typically need direct access to your Validation Result Store. Instead, your Data Context will use your Validation Result Store behind the scenes when storing or retrieving Validation Results. Most of your interaction with the Validation Results Store will take place during Setup, if you have need to configure your Validation Result Store beyond the default that is provided when you initialize your Data Context.
To configure a Validation Result Store, see Configure Validation Result Stores.