[arrow-datafusion] branch master updated: Add/Remove Division Rules (#3824)

[al...@apache.org]

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alamb pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/arrow-datafusion.git


The following commit(s) were added to refs/heads/master by this push:
     new 62aeb7594 Add/Remove Division Rules (#3824)
62aeb7594 is described below

commit 62aeb7594cedf4170034fcbe44605690050b19cd
Author: Burak <bu...@gmail.com>
AuthorDate: Tue Oct 18 15:53:37 2022 +0300

    Add/Remove Division Rules (#3824)
    
    * Add/Remove Division Rules
    
    * Check for nullability and fix linting
---
 datafusion/optimizer/src/simplify_expressions.rs | 32 ++++++++++++++++++++----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/datafusion/optimizer/src/simplify_expressions.rs b/datafusion/optimizer/src/simplify_expressions.rs
index a9970abf6..d528bd00f 100644
--- a/datafusion/optimizer/src/simplify_expressions.rs
+++ b/datafusion/optimizer/src/simplify_expressions.rs
@@ -788,12 +788,22 @@ impl<'a, S: SimplifyInfo> ExprRewriter for Simplifier<'a, S> {
                 op: Divide,
                 right,
             }) if is_null(&right) => *right,
-            // A / A --> 1 (if a is not nullable)
+            // 0 / 0 -> null
             Expr::BinaryExpr(BinaryExpr {
                 left,
                 op: Divide,
                 right,
-            }) if !info.nullable(&left)? && left == right => lit(1),
+            }) if is_zero(&left) && is_zero(&right) => {
+                Expr::Literal(ScalarValue::Int32(None))
+            }
+            // A / 0 -> DivideByZero Error
+            Expr::BinaryExpr(BinaryExpr {
+                left,
+                op: Divide,
+                right,
+            }) if !info.nullable(&left)? && is_zero(&right) => {
+                return Err(DataFusionError::ArrowError(ArrowError::DivideByZero))
+            }
 
             //
             // Rules for Modulo
@@ -1179,13 +1189,25 @@ mod tests {
     }
 
     #[test]
-    fn test_simplify_divide_by_same_non_null() {
-        let expr = binary_expr(col("c2_non_null"), Operator::Divide, col("c2_non_null"));
-        let expected = lit(1);
+    fn test_simplify_divide_zero_by_zero() {
+        // 0 / 0 -> null
+        let expr = binary_expr(lit(0), Operator::Divide, lit(0));
+        let expected = Expr::Literal(ScalarValue::Int32(None));
 
         assert_eq!(simplify(expr), expected);
     }
 
+    #[test]
+    #[should_panic(
+        expected = "called `Result::unwrap()` on an `Err` value: ArrowError(DivideByZero)"
+    )]
+    fn test_simplify_divide_by_zero() {
+        // A / 0 -> DivideByZeroError
+        let expr = binary_expr(col("c2_non_null"), Operator::Divide, lit(0));
+
+        simplify(expr);
+    }
+
     #[test]
     fn test_simplify_modulo_by_null() {
         let null = Expr::Literal(ScalarValue::Null);