update base on comment

src/hooks/utility/prepare.rs

@@ -129,18 +129,21 @@ pub fn execute_query<T: pgbox::WhoAllocated>(
             return Ok(true);
         }
 
-        // we need to make Duckdb replan the `PREPARE` statement when search path changed.
+        // We need to ensure that DuckDB replans the PREPARE statement when the search path changes,
+        // in order to match PostgreSQL’s default behavior.
+
         #[cfg(not(feature = "pg17"))]
         let need_replan = !pg_sys::OverrideSearchPathMatchesCurrent((*plan_source).search_path);
-
         #[cfg(feature = "pg17")]
         let need_replan = !pg_sys::SearchPathMatchesCurrentEnvironment((*plan_source).search_path);
 
+        // For PostgreSQL 13
         #[cfg(feature = "pg13")]
         let cached_plan = pg_sys::GetCachedPlan(plan_source, null_mut(), false, null_mut());
-
+        // For PostgreSQL 14 and above
         #[cfg(not(feature = "pg13"))]
         let cached_plan = pg_sys::GetCachedPlan(plan_source, null_mut(), null_mut(), null_mut());
+
         if cached_plan.is_null() || (*cached_plan).stmt_list.is_null() {
             return Ok(true);
         }

tests/scan.rs

@@ -644,5 +644,8 @@ async fn test_prepare_search_path(mut conn: PgConnection, tempdir: TempDir) -> R
     let result: Vec<(bool,)> = "EXECUTE q1(true)".fetch_collect(&mut conn);
     assert_eq!(result.len(), 1);
 
+    "DEALLOCATE q1".execute(&mut conn);
+    assert!("EXECUTE q1(true)".execute_result(&mut conn).is_err());
+
     Ok(())
 }