3.15.12 Model Metadata

Metadata for the model. It is a column in the Section 3.13.1.1, “The Model Catalog Table” and a parameter in ML_MODEL_IMPORT. The default value for a model_metadata field is NULL.

MySQL 8.1.0 adds several fields that replace deprecated columns in the Section 3.13.1.1, “The Model Catalog Table”. It also adds fields that support ONNX model import. See: Section 3.13.2, “ONNX Model Import”.

model_metadata contains the following metadata as key-value pairs in JSON format:

• task: string

  The task type specified in the ML_TRAIN query. The default is classification when used with ML_MODEL_IMPORT. This was added in MySQL 8.1.0.

• build_timestamp: number

  A timestamp indicating when the model was created, in UNIX epoch time. A model is created when the ML_TRAIN routine finishes executing. This was added in MySQL 8.1.0.

• target_column_name: string

  The name of the column in the training table that was specified as the target column. This was added in MySQL 8.1.0.

• train_table_name: string

  The name of the input table specified in the ML_TRAIN query. This was added in MySQL 8.1.0.

• column_names: JSON array

  The feature columns used to train the model. This was added in MySQL 8.1.0.

• model_explanation: JSON object

  The model explanation generated during training. See Section 3.13.7, “Model Explanations”. This was added in MySQL 8.1.0.

• notes: string

  The notes specified in the ML_TRAIN query. It also records any error messages that occur during model training. This was added in MySQL 8.1.0.

• format: string

  The model serialization format. HWMLv1.0 for a HeatWave AutoML model or ONNX for a ONNX model. The default is ONNX when used with ML_MODEL_IMPORT.

• status: Creating | Ready | Error

  The status of the model. The default is Ready when used with ML_MODEL_IMPORT.

  • Creating

    The model is still being created.

  • Ready

    The model is trained and active.

  • Error

    Either training was canceled or an error occurred during training. Any error message appears in the notes column. As of MySQL 8.1.0, the error message also appears in model_metadata notes.

• model_quality: string

  The quality of the model object. Either low or high. This was added in MySQL 8.1.0.

• training_time: number

  The time in seconds taken to train the model.

• algorithm_name: string

  The name of the chosen algorithm.

• training_score: number

  The cross-validation score achieved for the model by training.

• n_rows: number

  The number of rows in the training table.

• n_columns: number

  The number of columns in the training table.

• n_selected_columns: number

  The number of rows selected by feature selection.

• n_selected_rows: number

  The number of rows selected by adaptive sampling.

• optimization_metric: string

  The optimization metric used for training.

• selected_column_names: JSON array

  The names of the columns selected by feature selection.

• contamination: number

  The contamination factor for a model. This was added in MySQL 8.1.0.

• options: JSON object

  The options specified in the ML_TRAIN query. This was added in MySQL 8.1.0.

• training_params: JSON object

  Internal task dependent parameters used during ML_TRAIN. This was added in MySQL 8.1.0.

• onnx_inputs_info: JSON object

  Information about the format of the ONNX model inputs. This was added in MySQL 8.1.0, and only applies to ONNX models. See Section 3.13.2, “ONNX Model Import”.

  Do not provide onnx_inputs_info if the model is not ONNX format. This will cause an error.

  • data_types_map: JSON object

    This maps the data type of each column to an ONNX model data type. The default value is:

    JSON_OBJECT("tensor(int64)": "int64", "tensor(float)": "float32", "tensor(string)": "str_")

• onnx_outputs_info: JSON object

  Information about the format of the ONNX model outputs. This was added in MySQL 8.1.0, and only applies to ONNX models. See Section 3.13.2, “ONNX Model Import”.

  Do not provide onnx_outputs_info if the model is not ONNX format, or if task is NULL. This will cause an error.

  • predictions_name: string

    This name determines which of the ONNX model outputs is associated with predictions.

  • prediction_probabilities_name: string

    This name determines which of the ONNX model outputs is associated with prediction probabilities.

  • labels_map: JSON object

    This maps prediction probabilities to predictions, known as labels.