UBarney commented on code in PR #14567:
URL: https://github.com/apache/datafusion/pull/14567#discussion_r1950259492


##########
datafusion/physical-optimizer/src/pruning.rs:
##########
@@ -1710,6 +1717,56 @@ fn build_like_match(
     Some(combined)
 }
 
+// For predicate `col NOT LIKE 'foo%'`, we rewrite it as `(col_min NOT LIKE 
'foo%' OR col_max NOT LIKE 'foo%')`. If both col_min and col_max have the 
prefix foo, we skip the entire row group (as we can be certain that all data in 
this row group has the prefix foo).
+fn build_not_like_match(
+    expr_builder: &mut PruningExpressionBuilder<'_>,
+) -> Option<Arc<dyn PhysicalExpr>> {
+    // col NOT LIKE 'prefix%' ->  !(col_min LIKE 'prefix%' && col_max LIKE 
'prefix%') -> (col_min NOT LIKE 'prefix%' || col_max NOT LIKE 'prefix%')
+
+    let min_column_expr = expr_builder.min_column_expr().ok()?;
+    let max_column_expr = expr_builder.max_column_expr().ok()?;
+
+    let scalar_expr = expr_builder.scalar_expr();
+
+    let pattern = extract_string_literal(scalar_expr)?;
+
+    let chars: Vec<char> = pattern.chars().collect();
+    for i in 0..chars.len() - 1 {
+        // Check if current char is a wildcard and is not escaped with 
backslash
+        if (chars[i] == '%' || chars[i] == '_') && (i == 0 || chars[i - 1] != 
'\\') {
+            // Example: For pattern "foo%bar", the row group might include 
values like
+            // ["foobar", "food", "foodbar"], making it unsafe to prune.

Review Comment:
   Added a comment to explain why it goes wrong. Please take another look.
   



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