RETRAIN Statement

Description

The RETRAIN statement is used to retrain the already trained predictors with the new data. The predictor is updated to leverage the new data in optimizing its predictive capabilities.

Retraining takes at least as much time as the training process of the predictor did because now the dataset used to retrain has new or updated data.

Syntax

Here is the syntax:

RETRAIN mindsdb.[predictor_name];

On execution, we get:

Query OK, 0 rows affected (0.058 sec)

When to RETRAIN the Model?

It is advised to RETRAIN the predictor whenever the update_status column value from the mindsdb.predictors table is set to available.

Here is when the update_status column value is set to available:

• When the new version of MindsDB is available that causes the predictor to become obsolete.
• When the new data is available in the table that was used to train the predictor.

To find out whether you need to retrain your model, query the mindsdb.predictors table and look for the update_status column.

Here are the possible values of the update_status column:

Name	Description
available	It indicates that the model should be updated.
updating	It indicates that the retraining process of the model takes place.
up_to_date	It indicates that your model is up to date and does not need to be retrained.

Let's run the query.

SELECT name, update_status
FROM mindsdb.predictors
WHERE name = '[predictor_name]';

On execution, we get:

+------------------+---------------+
| name             | update_status |
+------------------+---------------+
| [predictor_name] | up_to_date    |
+------------------+---------------+

Where:

Name	Description
[predictor_name]	Name of the model to be retrained.
update_status	Column informing whether the model needs to be retrained.

Example

Let's look at an example using the home_rentals_model model.

First, we check the status of the predictor.

SELECT name, update_status
FROM mindsdb.predictors
WHERE name = 'home_rentals_model';

On execution, we get:

+--------------------+---------------+
| name               | update_status |
+--------------------+---------------+
| home_rentals_model | available     |
+--------------------+---------------+

The available value of the update_status column informs us that the new data is available, and we can retrain the model.

RETRAIN mindsdb.home_rentals_model;

On execution, we get:

Query OK, 0 rows affected (0.058 sec)

Now, let's check the status again.

SELECT  name, update_status
FROM mindsdb.predictors
WHERE name = 'home_rentals_model';

On execution, we get:

+--------------------+---------------+
| name               | update_status |
+--------------------+---------------+
| home_rentals_model | updating      |
+--------------------+---------------+

And after the retraining process is completed:

SELECT  name, update_status
FROM mindsdb.predictors
WHERE name = 'home_rentals_model';

On execution, we get:

+--------------------+---------------+
| name               | update_status |
+--------------------+---------------+
| home_rentals_model | up_to_date    |
+--------------------+---------------+