Deployments

A model is automatically deployed and used for predictions if its key metric (R² for regression, F₁ for classification) is improved during training over the previous version. Alternatively, if you want to manage deploys manually, you can always change which model is currently responsible for making predictions.

API

pgml.deploy(
	project_name TEXT,
	strategy TEXT DEFAULT 'best_score',
	algorithm TEXT DEFAULT NULL
)

Parameters

Strategies

There are 3 different deployment strategies available:

The default deployment behavior allows any algorithm to qualify. It's automatically used during training, but can be manually executed as well:

• SQL
• Output

SELECT * FROM pgml.deploy(
	'Handwritten Digit Image Classifier',
	strategy => 'best_score'
);

              project               |  strategy  | algorithm
------------------------------------+------------+-----------
 Handwritten Digit Image Classifier | best_score | xgboost
(1 row)

Specific Algorithms

Deployment candidates can be restricted to a specific algorithm by including the algorithm parameter. This is useful when you're training multiple algorithms using different hyperparameters and want to restrict the deployment a single algorithm only:

• SQL
• Output

SELECT * FROM pgml.deploy(
    project_name => 'Handwritten Digit Image Classifier', 
    strategy => 'best_score', 
    algorithm => 'svm'
);

            project_name            |    strategy    | algorithm
------------------------------------+----------------+----------------
 Handwritten Digit Image Classifier | classification | svm
(1 row)

Rolling Back

In case the new model isn't performing well in production, it's easy to rollback to the previous version. A rollback creates a new deployment for the old model. Multiple rollbacks in a row will oscillate between the two most recently deployed models, making rollbacks a safe and reversible operation.

• Rollback 1
• Output
• Rollback 2
• Output

SELECT * FROM pgml.deploy(
	'Handwritten Digit Image Classifier',
	strategy => 'rollback'
);

             project               | strategy | algorithm
------------------------------------+----------+-----------
 Handwritten Digit Image Classifier | rollback | linear
(1 row)

SELECT * FROM pgml.deploy(
	'Handwritten Digit Image Classifier',
	strategy => 'rollback'
);

              project               | strategy | algorithm
------------------------------------+----------+-----------
 Handwritten Digit Image Classifier | rollback | xgboost
(1 row)