机器学习使用文档

-- Exit on error (psql)
-- \set ON_ERROR_STOP true
\timing on

SELECT pgml.load_dataset('breast_cancer');

-- view the dataset
SELECT * FROM pgml.breast_cancer LIMIT 10;

-- train a simple model to classify the data
SELECT * FROM pgml.train('Breast Cancer Detection', 'classification', 'pgml.breast_cancer', 'malignant');

-- check out the predictions
SELECT malignant, pgml.predict(
    'Breast Cancer Detection', 
    (
        "mean radius", 
        "mean texture", 
        "mean perimeter", 
        "mean area",
        "mean smoothness",
        "mean compactness",
        "mean concavity",
        "mean concave points",
        "mean symmetry",
        "mean fractal dimension",
        "radius error",
        "texture error",
        "perimeter error",
        "area error",
        "smoothness error",
        "compactness error",
        "concavity error",
        "concave points error",
        "symmetry error",
        "fractal dimension error",
        "worst radius",
        "worst texture",
        "worst perimeter",
        "worst area",
        "worst smoothness",
        "worst compactness",
        "worst concavity",
        "worst concave points",
        "worst symmetry",
        "worst fractal dimension"
    )
) AS prediction
FROM pgml.breast_cancer
LIMIT 10;

-- view raw class probabilities
SELECT malignant, pgml.predict_proba(
    'Breast Cancer Detection',
    ARRAY[
        "mean radius",
        "mean texture",
        "mean perimeter",
        "mean area",
        "mean smoothness",
        "mean compactness",
        "mean concavity",
        "mean concave points",
        "mean symmetry",
        "mean fractal dimension",
        "radius error",
        "texture error",
        "perimeter error",
        "area error",
        "smoothness error",
        "compactness error",
        "concavity error",
        "concave points error",
        "symmetry error",
        "fractal dimension error",
        "worst radius",
        "worst texture",
        "worst perimeter",
        "worst area",
        "worst smoothness",
        "worst compactness",
        "worst concavity",
        "worst concave points",
        "worst symmetry",
        "worst fractal dimension"
    ]
) AS prediction
FROM pgml.breast_cancer
LIMIT 10;

--
-- After a project has been trained, omitted parameters will be reused from previous training runs
-- In these examples we'll reuse the training data snapshots from the initial call.
--

-- linear models
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'ridge');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'stochastic_gradient_descent');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'perceptron');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'passive_aggressive');

-- support vector machines
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'svm');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'nu_svm');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'linear_svm');

-- ensembles
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'ada_boost');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'bagging');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'extra_trees', hyperparams => '{"n_estimators": 10}');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'gradient_boosting_trees', hyperparams => '{"n_estimators": 10}');
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'random_forest', hyperparams => '{"n_estimators": 10}');

-- other
-- Gaussian Process is too expensive for normal tests on even a toy dataset
-- SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'gaussian_process', hyperparams => '{"max_iter_predict": 100, "warm_start": true}');

-- Gradient Boosting
SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'xgboost', hyperparams => '{"n_estimators": 10}');
-- SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'xgboost_random_forest', hyperparams => '{"n_estimators": 10}');
-- SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'lightgbm', hyperparams => '{"n_estimators": 1}');
-- Histogram Gradient Boosting is too expensive for normal tests on even a toy dataset
-- SELECT * FROM pgml.train('Breast Cancer Detection', algorithm => 'hist_gradient_boosting', hyperparams => '{"max_iter": 2}');


-- check out all that hard work
SELECT trained_models.* FROM pgml.trained_models 
JOIN pgml.models on models.id = trained_models.id
ORDER BY models.metrics->>'f1' DESC LIMIT 5;

-- deploy the random_forest model for prediction use
SELECT * FROM pgml.deploy('Breast Cancer Detection', 'most_recent', 'random_forest');
-- check out that throughput
SELECT * FROM pgml.deployed_models ORDER BY deployed_at DESC LIMIT 5;

-- do a hyperparam search on your favorite algorithm
SELECT pgml.train(
    'Breast Cancer Detection', 
    algorithm => 'xgboost', 
    search => 'grid', 
    search_params => '{
        "n_estimators": [2, 4],
        "max_depth": [1, 2, 3]
    }'
);

-- deploy the "best" model for prediction use
SELECT * FROM pgml.deploy('Breast Cancer Detection', 'best_score');
SELECT * FROM pgml.deploy('Breast Cancer Detection', 'most_recent');
SELECT * FROM pgml.deploy('Breast Cancer Detection', 'rollback');
SELECT * FROM pgml.deploy('Breast Cancer Detection', 'best_score', 'svm');

-- check out the improved predictions
SELECT malignant, pgml.predict(
    'Breast Cancer Detection', 
    (
        "mean radius", 
        "mean texture", 
        "mean perimeter", 
        "mean area",
        "mean smoothness",
        "mean compactness",
        "mean concavity",
        "mean concave points",
        "mean symmetry",
        "mean fractal dimension",
        "radius error",
        "texture error",
        "perimeter error",
        "area error",
        "smoothness error",
        "compactness error",
        "concavity error",
        "concave points error",
        "symmetry error",
        "fractal dimension error",
        "worst radius",
        "worst texture",
        "worst perimeter",
        "worst area",
        "worst smoothness",
        "worst compactness",
        "worst concavity",
        "worst concave points",
        "worst symmetry",
        "worst fractal dimension"
    )
) AS prediction
FROM pgml.breast_cancer 
LIMIT 10;

SELECT pgml.load_dataset('diabetes');

-- view the dataset
SELECT * FROM pgml.diabetes LIMIT 10;

-- train a simple model on the data
SELECT * FROM pgml.train('Diabetes Progression', 'regression', 'pgml.diabetes', 'target');

-- check out the predictions
SELECT target, pgml.predict('Diabetes Progression', (age, sex, bmi, bp, s1, s2, s3, s4, s5, s6)) AS prediction
FROM pgml.diabetes 
LIMIT 10;

-- Check predictions against a specific model id
SELECT model_id, target, pgml.predict(model_id, (age, sex, bmi, bp, s1, s2, s3, s4, s5, s6)) AS prediction
FROM pgml.diabetes
CROSS JOIN LATERAL (
    SELECT pgml.models.id AS model_id FROM pgml.models
    INNER JOIN pgml.projects
    ON pgml.models.project_id = pgml.projects.id
    WHERE pgml.projects.name = 'Diabetes Progression'
    LIMIT 1
) models
LIMIT 10;

--
-- After a project has been trained, omitted parameters will be reused from previous training runs
-- In these examples we'll reuse the training data snapshots from the initial call.
--

-- linear models
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'ridge');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'lasso');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'elastic_net');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'least_angle');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'lasso_least_angle');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'orthogonal_matching_pursuit');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'bayesian_ridge');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'automatic_relevance_determination');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'stochastic_gradient_descent');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'passive_aggressive');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'ransac');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'theil_sen', hyperparams => '{"max_iter": 10, "max_subpopulation": 100}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'huber');
-- Quantile Regression too expensive for normal tests on even a toy dataset
-- SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'quantile');

-- support vector machines
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'svm', hyperparams => '{"max_iter": 100}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'nu_svm', hyperparams => '{"max_iter": 10}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'linear_svm', hyperparams => '{"max_iter": 100}');

-- ensembles
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'ada_boost', hyperparams => '{"n_estimators": 5}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'bagging', hyperparams => '{"n_estimators": 5}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'extra_trees', hyperparams => '{"n_estimators": 5}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'gradient_boosting_trees', hyperparams => '{"n_estimators": 5}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'random_forest', hyperparams => '{"n_estimators": 5}');

-- other
-- Kernel Ridge is too expensive for normal tests on even a toy dataset
-- SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'kernel_ridge');
-- Gaussian Process is too expensive for normal tests on even a toy dataset
-- SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'gaussian_process');

-- gradient boosting
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'xgboost', hyperparams => '{"n_estimators": 10}');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'catboost', hyperparams => '{"n_estimators": 10}');
-- SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'xgboost_random_forest', hyperparams => '{"n_estimators": 10}');
-- SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'lightgbm', hyperparams => '{"n_estimators": 1}');
-- Histogram Gradient Boosting is too expensive for normal tests on even a toy dataset
-- SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'hist_gradient_boosting', hyperparams => '{"max_iter": 10}');

-- runtimes
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'linear', runtime => 'python');
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'linear', runtime => 'rust');

--SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'xgboost', runtime => 'python', hyperparams => '{"n_estimators": 1}'); -- too slow
SELECT * FROM pgml.train('Diabetes Progression', algorithm => 'xgboost', runtime => 'rust', hyperparams => '{"n_estimators": 10}');

-- check out all that hard work
SELECT trained_models.* FROM pgml.trained_models 
JOIN pgml.models on models.id = trained_models.id
ORDER BY models.metrics->>'mean_squared_error' DESC LIMIT 5;

-- deploy the random_forest model for prediction use
SELECT * FROM pgml.deploy('Diabetes Progression', 'most_recent', 'random_forest');
-- check out that throughput
SELECT * FROM pgml.deployed_models ORDER BY deployed_at DESC LIMIT 5;

-- do a hyperparam search on your favorite algorithm
SELECT pgml.train(
    'Diabetes Progression', 
    algorithm => 'xgboost',
    hyperparams => '{"eval_metric": "rmse"}'::JSONB,
    search => 'grid', 
    search_params => '{
        "max_depth": [1, 2], 
        "n_estimators": [20, 40]
    }'
);

-- deploy the "best" model for prediction use
SELECT * FROM pgml.deploy('Diabetes Progression', 'best_score');
SELECT * FROM pgml.deploy('Diabetes Progression', 'most_recent');
SELECT * FROM pgml.deploy('Diabetes Progression', 'rollback');
SELECT * FROM pgml.deploy('Diabetes Progression', 'best_score', 'svm');

-- check out the improved predictions
SELECT target, pgml.predict('Diabetes Progression', (age, sex, bmi, bp, s1, s2, s3, s4, s5, s6)) AS prediction
FROM pgml.diabetes 
LIMIT 10;

-- This example trains models on the sklean digits dataset
-- which is a copy of the test set of the UCI ML hand-written digits datasets
-- https://archive.ics.uci.edu/ml/datasets/Optical+Recognition+of+Handwritten+Digits
--
-- This demonstrates using a table with a single array feature column
-- for clustering. You could do something similar with a vector column
--

-- Exit on error (psql)
-- \set ON_ERROR_STOP true
\timing on

SELECT pgml.load_dataset('digits');

-- create an unlabeled table of the images for unsupervised learning
CREATE VIEW pgml.digit_vectors AS
SELECT image FROM pgml.digits;

-- view the dataset
SELECT left(image::text, 40) || ',...}' FROM pgml.digit_vectors LIMIT 10;

-- train a simple model to classify the data
SELECT * FROM pgml.train('Handwritten Digit Clusters', 'clustering', 'pgml.digit_vectors', hyperparams => '{"n_clusters": 10}');

-- check out the predictions
SELECT target, pgml.predict('Handwritten Digit Clusters', image) AS prediction
FROM pgml.digits
LIMIT 10;

SELECT * FROM pgml.train('Handwritten Digit Clusters', algorithm => 'affinity_propagation');
SELECT * FROM pgml.train('Handwritten Digit Clusters', algorithm => 'birch', hyperparams => '{"n_clusters": 10}');
SELECT * FROM pgml.train('Handwritten Digit Clusters', algorithm => 'kmeans', hyperparams => '{"n_clusters": 10}');
SELECT * FROM pgml.train('Handwritten Digit Clusters', algorithm => 'mini_batch_kmeans', hyperparams => '{"n_clusters": 10}');

-- This example reduces the dimensionality of images in the sklean digits dataset
-- which is a copy of the test set of the UCI ML hand-written digits datasets
-- https://archive.ics.uci.edu/ml/datasets/Optical+Recognition+of+Handwritten+Digits
--
-- This demonstrates using a table with a single array feature column
-- for decomposition to reduce dimensionality.
--
-- Exit on error (psql)
-- \set ON_ERROR_STOP true
\timing on

SELECT pgml.load_dataset('digits');

-- view the dataset
SELECT left(image::text, 40) || ',...}', target FROM pgml.digits LIMIT 10;

-- create a view of just the vectors for decomposition, without any labels
CREATE VIEW digit_vectors AS
SELECT image FROM pgml.digits;

SELECT * FROM pgml.train('Handwritten Digits Reduction', 'decomposition', 'digit_vectors');

-- check out the decomposed vectors
SELECT target, pgml.decompose('Handwritten Digits Reduction', image) AS pca
FROM pgml.digits
LIMIT 10;

--
-- After a project has been trained, omitted parameters will be reused from previous training runs
-- In these examples we'll reuse the training data snapshots from the initial call.
--

-- We can reduce the image vectors from 64 dimensions to 3 components
SELECT * FROM pgml.train('Handwritten Digits Reduction', hyperparams => '{"n_components": 3}');

-- check out the reduced vectors
SELECT target, pgml.decompose('Handwritten Digits Reduction', image) AS pca
FROM pgml.digits
LIMIT 10;

-- check out all that hard work
SELECT trained_models.* FROM pgml.trained_models
                                 JOIN pgml.models on models.id = trained_models.id
ORDER BY models.metrics->>'cumulative_explained_variance' DESC LIMIT 5;

-- deploy the PCA model for prediction use
SELECT * FROM pgml.deploy('Handwritten Digits Reduction', 'most_recent', 'pca');
-- check out that throughput
SELECT * FROM pgml.deployed_models ORDER BY deployed_at DESC LIMIT 5;

-- deploy the "best" model for prediction use
SELECT * FROM pgml.deploy('Handwritten Digits Reduction', 'best_score');
SELECT * FROM pgml.deploy('Handwritten Digits Reduction', 'most_recent');
SELECT * FROM pgml.deploy('Handwritten Digits Reduction', 'rollback');
SELECT * FROM pgml.deploy('Handwritten Digits Reduction', 'best_score', 'pca');

-- check out the improved predictions
SELECT target, pgml.predict('Handwritten Digits Reduction', image) AS prediction
FROM pgml.digits
LIMIT 10;

-- load the diamonds dataset, that contains text categorical variables
SELECT pgml.load_dataset('jdxcosta/diamonds');

-- view the data
SELECT * FROM pgml."jdxcosta/diamonds" LIMIT 10;

-- drop the Unamed column, since it's not useful for training (you could create a view instead)
ALTER TABLE pgml."jdxcosta/diamonds" DROP COLUMN "Unnamed: 0";

-- train a model using preprocessors to scale the numeric variables, and target encode the categoricals
SELECT pgml.train(
       project_name => 'Diamond prices',
       task => 'regression',
       relation_name => 'pgml.jdxcosta/diamonds',
       y_column_name => 'price',
       algorithm => 'lightgbm',
       preprocess => '{
                      "carat": {"scale": "standard"},
                      "depth": {"scale": "standard"},
                      "table": {"scale": "standard"},
                      "cut": {"encode": "target", "scale": "standard"},
                      "color": {"encode": "target", "scale": "standard"},
                      "clarity": {"encode": "target", "scale": "standard"}
                  }'
);

-- run some predictions, notice we're passing a heterogeneous row (tuple) as input, rather than a homogenous ARRAY[].
SELECT price, pgml.predict('Diamond prices', (carat, cut, color, clarity, depth, "table", x, y, z)) AS prediction
FROM pgml."jdxcosta/diamonds"
LIMIT 10;

-- This is a difficult dataset for more algorithms, which makes it a good challenge for preprocessing, and additional
-- feature engineering. What's next?