You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Apache Spark (JIRA)" <ji...@apache.org> on 2018/01/09 18:37:00 UTC
[jira] [Assigned] (SPARK-23007) Add schema evolution test suite for
file-based data sources
[ https://issues.apache.org/jira/browse/SPARK-23007?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Apache Spark reassigned SPARK-23007:
------------------------------------
Assignee: (was: Apache Spark)
> Add schema evolution test suite for file-based data sources
> -----------------------------------------------------------
>
> Key: SPARK-23007
> URL: https://issues.apache.org/jira/browse/SPARK-23007
> Project: Spark
> Issue Type: Bug
> Components: SQL, Tests
> Affects Versions: 2.2.1
> Reporter: Dongjoon Hyun
>
> A schema can evolve in several ways and the followings are already supported in file-based data sources.
> 1. Add a column
> 2. Remove a column
> 3. Change a column position
> 4. Change a column type
> This issue aims to guarantee users a backward-compatible schema evolution coverage on file-based data sources and to prevent future regressions by *adding schema evolution test suites explicitly*.
> Here, we consider safe evolution without data loss. For example, data type evolution should be from small types to larger types like `int`-to-`long`, not vice versa.
> As of today, in the master branch, file-based data sources have schema evolution coverages like the followings.
> || File Format || Coverage || Note ||
> | TEXT | N/A | Schema consists of a single string column. |
> | CSV | 1, 2, 4 | |
> | JSON | 1, 2, 3, 4 | |
> | ORC | 1, 2, 3, 4 | Native vectorized ORC reader has the widest coverage. |
> | PARQUET | 1, 2, 3 | |
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org