---
library_name: lightgbm
tags:
- text-to-sql
- sql
- reranker
- lightgbm
- lambdarank
- duckdb
- codet5
---

# Text-to-SQL LightGBM Reranker

This repository contains a trained LightGBM LambdaRank reranker for selecting the best SQL candidate from CodeT5-generated SQL candidates.

## Performance Summary

- Rows: 4701
- Candidate upper bound: 0.4482025101042331
- Rule reranker exact: 0.24803233354605403
- Validation ML exact: 0.3995749202975558
- Validation ML correct: 376 / 941
- Full ML exact: 0.43671559242714314

## Files

- sql_reranker_lightgbm.txt: trained LightGBM model
- feature_columns.json: exact feature column order used during training
- feature_importance.csv: LightGBM feature importance
- summary.json: training summary
- inference.py: helper functions for loading and scoring

## Intended Pipeline

Question -> NER + value index -> CodeT5 candidates -> feature extraction -> LightGBM reranker -> best SQL

## Important

This reranker does not generate SQL by itself. It only ranks already-generated SQL candidates.

At inference time, use the same feature extraction logic as training and reindex with feature_columns.json.