UPDATE / DELETE fail with "No field named __common_expr_1" when SET or WHERE repeats an expression

Abierto
  • ¿Algo no está bien?
#27,235 0 comentarios 0 reacciones 0 asignados Ver en GitHub

Los mantenedores suelen responder en 1 día

@v28k ya está trabajando en esto.

Desde el 8/11/2026.

Evaluación

Dificultad
4/5
Tiempo estimado
3-5 días
Aptitud para principiantes
20/100
Tipo de issue
Error
Claridad
Bien especificado
Estado de actividad
Estancado
Stack tecnológico
rust
Área
backend-api-design, databases

Línea de trabajo

Start by tracing extract_update_assignments and extract_dml_filters in the physical planner, then follow how common subexpression elimination moves expressions into projections. Check the UPDATE and DELETE planning paths against the table provider's schema. Done means the three reproduced statements execute without the missing __common_expr_N schema error and produce the expected row changes.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

bug
Describe the bug

An UPDATE or DELETE on an in-memory table fails at planning time with a schema error regarding an internal column when its SET expressions or WHERE clause contain the same expression more than once (for example, COALESCE(c0, 0) on an INT column, where the column is coerced/cast to Int64 twice to match the integer literal):

UPDATE operation on table 't' caused by Schema error: No field named __common_expr_1. Valid fields are c0, c1.

Common subexpression elimination moves the repeated expression into an underlying projection below the UPDATE assignment projection (or below the Filter node). When the physical planner extracts the assignments (extract_update_assignments) and filters (extract_dml_filters) and hands them to the table provider, the provider evaluates them directly against the table's schema, where __common_expr_1 does not exist.

To Reproduce

CREATE TABLE t (c0 INT, c1 VARCHAR);
INSERT INTO t VALUES (1, 'a'), (NULL, 'b');

UPDATE t SET c0 = COALESCE(c0, 0); -- Schema error: No field named __common_expr_1
UPDATE t SET c1 = 'z' WHERE COALESCE(c0, 0) > 0 AND COALESCE(c0, 0) < 5; -- Schema error: No field named __common_expr_N
DELETE FROM t WHERE COALESCE(c0, 0) > 0 AND COALESCE(c0, 0) < 5; -- Schema error: No field named __common_expr_N

Expected behavior

The first UPDATE should update 2 rows ((1, 'a'), (0, 'b')). The second UPDATE should update 1 row, and the DELETE should delete 1 row. The same expressions execute without error in a SELECT.

Additional context

Reproduced on main at commit bc86321 (57.0.0-dev) and with datafusion-python 55.0.0. Found via an automated SQL fuzzer comparing execution plans.

Willingness to contribute

I plan to contribute a fix for this bug independently

Lenguaje dominante
Rust
Estrellas
9.6k
Forks
2.6k
Merge medio
3 d 4 h
PR fusionados (30 d)
345

Preparar el entorno

Abrir en Codespaces

Inicia el contenedor de desarrollo del proyecto en tu navegador, con tu propia cuenta de GitHub.

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

Más de apache/datafusion

Todos los issues de apache/datafusion

Issues similares

Más issues de Rust

Recibe los nuevos issues en tu correo

Un resumen breve de issues de GitHub para principiantes.