From 0ddb1d7149f256c804d1fd4029aafc0ab544148d Mon Sep 17 00:00:00 2001
From: shenzhengntu <142518889+shenzhengntu@users.noreply.github.com>
Date: Wed, 22 Jul 2026 17:25:20 +0800
Subject: [PATCH] classification xgboost train bug
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\set ON_ERROR_STOP true
\timing on

-- 清理旧数据
DROP EXTENSION IF EXISTS pgml CASCADE;
DROP SCHEMA IF EXISTS pgml CASCADE;
CREATE EXTENSION pgml;

-- 加载数据集
SELECT pgml.load_dataset('breast_cancer');
-- 加载数据集
SELECT pgml.load_dataset('breast_cancer');

-- =============================================
-- 分类算法 Python vs Rust 对比测试
-- 指标: f1, 差异阈值: < 0.05 (random_forest < 0.1)
-- =============================================

-- === linear 分类 ===
SELECT * FROM pgml.train('Rust Classification Compare', 'classification', 'pgml.breast_cancer', 'malignant', algorithm => 'linear', runtime => 'python');
SELECT * FROM pgml.train('Rust Classification Compare', algorithm => 'linear', runtime => 'rust');
-- === xgboost 分类 ===
SELECT * FROM pgml.train('Rust Classification Compare', algorithm => 'xgboost', runtime => 'python', hyperparams => '{"n_estimators": 10}');
SELECT * FROM pgml.train('Rust Classification Compare', algorithm => 'xgboost', runtime => 'rust', hyperparams => '{"n_estimators": 10}');

-- xgboost rust "roc_auc" always 0.5-----

INFO:  Metrics: {"roc_auc": 0.5, "log_loss": 10.55341, "f1": 0.50526315, "precision": 0.33802816, "recall": 1.0, "accuracy": 0.33802816, "mcc": NaN, "fit_time": 0.006182069, "score_time": 0.000807744}
INFO:  Comparing to deployed model f1: Some(0.9292929172515868)
WARNING:  New model's f1 is not better than current model. New: 0.5052631497383118, Current 0.9292929172515868
WARNING:  Not deploying newly trained model.
           project           |      task      | algorithm | deployed
-----------------------------+----------------+-----------+----------
 Rust Classification Compare | classification | xgboost   | f


the reason is not update bst train
---
 src/booster.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/booster.rs b/src/booster.rs
index a965b6d..19504d3 100644
--- a/src/booster.rs
+++ b/src/booster.rs
@@ -148,8 +148,9 @@ impl Booster {
             dmats
         };
 
-        let bst = Booster::new_with_cached_dmats(&params.booster_params, &cached_dmats)?;
+        let mut bst = Booster::new_with_cached_dmats(&params.booster_params, &cached_dmats)?;
         for i in 0..params.boost_rounds as i32 {
+			bst.update(params.dtrain, i)?;
             if let Some(eval_sets) = params.evaluation_sets {
                 let mut dmat_eval_results = bst.eval_set(eval_sets, i)?;