[GitHub] [arrow-datafusion] jonmmease opened a new issue, #2462: Projection pushdown produces incorrect results when column names are reused

[GitBox <gi...@apache.org>]

jonmmease opened a new issue, #2462:
URL: https://github.com/apache/arrow-datafusion/issues/2462

   **Describe the bug**
   In certain situations where projections are used to overwrite a column's value, the projection pushdown optimization pass causes the incorrect column value to be produced.
   
   **To Reproduce**
   Here is a failing test that will be included in the follow-on PR
   
   ```rust
   #[tokio::test]
   async fn select_with_alias_overwrite() -> Result<()> {
       let schema = Schema::new(vec![Field::new("a", DataType::Int32, false)]);
   
       let batch = RecordBatch::try_new(
           Arc::new(schema.clone()),
           vec![Arc::new(Int32Array::from_slice(&[1, 10, 10, 100]))],
       )
       .unwrap();
   
       let ctx = SessionContext::new();
       let provider = MemTable::try_new(Arc::new(schema), vec![vec![batch]]).unwrap();
       ctx.register_table("t", Arc::new(provider)).unwrap();
   
       let df = ctx
           .table("t")
           .unwrap()
           .select(vec![col("a").alias("a")])
           .unwrap()
           .select(vec![(col("a").eq(lit(10))).alias("a")])
           .unwrap()
           .select(vec![col("a")])
           .unwrap();
   
       let results = df.collect().await.unwrap();
   
       #[rustfmt::skip]
           let expected = vec![
           "+-------+",
           "| a     |",
           "+-------+",
           "| false |",
           "| true  |",
           "| true  |",
           "| false |",
           "+-------+",
       ];
       assert_batches_eq!(expected, &results);
   
       Ok(())
   }
   ```
   presently, the values produced for column `a` are the original values `[1, 10, 10, 100]` rather than the expected values `[false, true, true, false]`.
   
   PR to follow shortly
   


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[GitHub] [arrow-datafusion] alamb closed issue #2462: Projection pushdown produces incorrect results when column names are reused

[GitBox <gi...@apache.org>]

alamb closed issue #2462: Projection pushdown produces incorrect results when column names are reused
URL: https://github.com/apache/arrow-datafusion/issues/2462


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