apache / apache/parquet-java

Add way to disables statistics on a per column basis

Abierto
#2,521 5 comentarios 0 reacciones 0 asignados Ver en GitHub
Component: Java Component: Parquet Priority: Major Type: enhancement
Lenguaje dominante
Java
Estrellas
3.1k
Forks
1.6k
Merge medio
3 d 12 h
PR fusionados (30 d)
33

Descripción

When you write dataset with BINARY columns that can be fairly large (several Mbs) you can often end with an OutOfMemory error where you either have to:

 

 - Throw more RAM

 - Increase number of output files

 - Play with Block size

 

Using a fork with increased checks frequency for row group size help but it is not enough. (PR: )

 

 

The OutOfMemory error is now caused due to the accumulation of min/max values for those columns for each BlockMetaData.

 

The "parquet.statistics.truncate.length" configuration is of no help because it is applied during the footer serialization whereas the OOM occurs before that.

 

I think it would be nice to have, like for dictionary or bloom filter, a way to disable the statistic on a per-column basis.

 

Could be very useful to lower memory consumption when stats of huge binary column are unnecessary.

 

 

 

**Reporter**: [Anthony Pessy](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=panthony) / @panthony
#### Original Issue Attachments:
- [add_config_to_opt-out_of_a_column's_statistics.patch](https://issues.apache.org/jira/secure/attachment/13011473/add_config_to_opt-out_of_a_column%27s_statistics.patch)
- [NoOpStatistics.java](https://issues.apache.org/jira/secure/attachment/13037932/NoOpStatistics.java)

**Note**: *This issue was originally created as [PARQUET-1911](https://issues.apache.org/jira/browse/PARQUET-1911). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*

Guía de contribución

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Línea de trabajo

Comienza leyendo los archivos adjuntos NoOpStatistics.java y add_config_to_opt-out_of_a_column's_statistics.patch; después, sigue cómo se acumulan las estadísticas en BlockMetaData antes de la serialización del footer. Se considera terminado cuando se proporcione una forma de deshabilitar las estadísticas por columna, de modo que las columnas BINARY grandes dejen de acumular valores min/max y provocar errores OutOfMemory.

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

Evaluación

Stack tecnológico
java
Área
data-engineering
Tipo de issue
Nueva funcionalidad
Dificultad
4/5
Tiempo estimado
3-5 días
Estado de actividad
Estancado
Claridad
Bastante claro
Aptitud para principiantes
35/100

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