You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Assaf Mendelson (JIRA)" <ji...@apache.org> on 2018/10/11 12:12:00 UTC
[jira] [Created] (SPARK-25709) Can't append to a data source V2
unless target already has schema information or fixed schema matching
dataframe
Assaf Mendelson created SPARK-25709:
---------------------------------------
Summary: Can't append to a data source V2 unless target already has schema information or fixed schema matching dataframe
Key: SPARK-25709
URL: https://issues.apache.org/jira/browse/SPARK-25709
Project: Spark
Issue Type: Bug
Components: SQL
Affects Versions: 2.4.0
Reporter: Assaf Mendelson
Let's assume we have a writer data source which writes to a dynamic schema (e.g. writing to a database table). If we have mode append but the table is missing then writing will fail.
The reason for this is that in the dataframeWriter save method we have val relation = DataSourceV2Relation.create(source, options) which in turn contains: val reader = source.createReader(options, userSpecifiedSchema)
The problem is that this sets the schema from the reader portion of the data source. If the data source can't infer the schema then we will fail to write (even thought the schema is actually part of the dataframe).
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org