[ 
https://issues.apache.org/jira/browse/SPARK-49743?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Nikhil Sheoran updated SPARK-49743:
-----------------------------------
    Description: 
The `OptimizeCsvJsonExprs` rule can potentially change the schema of the 
underlying `StructField` if there are differences in the field used to access 
the struct vs the field in the underlying struct.

This surfaces as a correctness issue where instead of picking the values for 
the corresponding column we end up returning NULL.

 

A simple example query is:
{code:java}
SELECT
  from_json('[{"a": '||id||', "b": '|| (2*id) ||'}]', 'array<struct<a: INT, b: 
INT>>').a,
  from_json('[{"a": '||id||', "b": '|| (2*id) ||'}]', 'array<struct<a: INT, b: 
INT>>').A
FROM
  range(3) as t{code}
 

 

Here, the result is `[0], [1], [2]` for `a` but `[null], [null], [null]` for 
`A`. Since struct field accessor is case-insensitive, the result should had 
been `[0], [1], [2]` for both.

  was:
The `OptimizeCsvJsonExprs` rule can potentially change the schema of the 
underlying `StructField` if there are differences in the field used to access 
the struct vs the field in the underlying struct.

This surfaces as a correctness issue where instead of picking the values for 
the corresponding column we end up returning NULL.

 

A simple example query is:
{code:java}
SELECT
  from_json('[\{"a": '||id||', "b": '|| (2*id) ||'}]', 'array<struct<a: INT, b: 
INT>>').a,
  from_json('[\{"a": '||id||', "b": '|| (2*id) ||'}]', 'array<struct<a: INT, b: 
INT>>').A
FROM
  range(3) as t{code}
 

 

Here, the result is `[0], [1], [2]` for `a` but `[null], [null], [null]` for 
`A`. Since struct field accessor is case-insensitive, the result should had 
been `[0], [1], [2]` for both.


> OptimizeCsvJsonExpr should not change the schema of underlying StructType in 
> GetArrayStructFields
> -------------------------------------------------------------------------------------------------
>
>                 Key: SPARK-49743
>                 URL: https://issues.apache.org/jira/browse/SPARK-49743
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 3.5.2
>            Reporter: Nikhil Sheoran
>            Priority: Major
>              Labels: pull-request-available
>
> The `OptimizeCsvJsonExprs` rule can potentially change the schema of the 
> underlying `StructField` if there are differences in the field used to access 
> the struct vs the field in the underlying struct.
> This surfaces as a correctness issue where instead of picking the values for 
> the corresponding column we end up returning NULL.
>  
> A simple example query is:
> {code:java}
> SELECT
>   from_json('[{"a": '||id||', "b": '|| (2*id) ||'}]', 'array<struct<a: INT, 
> b: INT>>').a,
>   from_json('[{"a": '||id||', "b": '|| (2*id) ||'}]', 'array<struct<a: INT, 
> b: INT>>').A
> FROM
>   range(3) as t{code}
>  
>  
> Here, the result is `[0], [1], [2]` for `a` but `[null], [null], [null]` for 
> `A`. Since struct field accessor is case-insensitive, the result should had 
> been `[0], [1], [2]` for both.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to