[jira] [Updated] (ARROW-6896) [Java] Vector schema root should not share vectors

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARROW-6896?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

ASF GitHub Bot updated ARROW-6896:
----------------------------------
    Labels: pull-request-available  (was: )

> [Java] Vector schema root should not share vectors
> --------------------------------------------------
>
>                 Key: ARROW-6896
>                 URL: https://issues.apache.org/jira/browse/ARROW-6896
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: Java
>            Reporter: Liya Fan
>            Assignee: Liya Fan
>            Priority: Major
>              Labels: pull-request-available
>
> Vector schema root should not share vectors. Otherwise, unexpectd behavior would happen. 
> Please note that VectorSchemaRoot is not just a container for vectors, it is also a resource (it implements the AutoClosable interface), and it manages the life cycle of its inner vectors.
> When two VectorSchemaRoots share vectors, something unexpected may happen. Consider the following scenario, which is frequently encountered in a SQL engine.
> 1. We create a batch:
> VectorSchemaRoot oldBatch = ...
> 2. We add a vector to it, which results in a new batch
> VectorSchemaRoot newBatch = oldBatch.addVector(vector);
> 3. We are done with the old batch, and release the resource
> oldBatch.close();
> 4. We continue to use the new batch, but gets an exception, because some inner vectors have been released by the old batch. 



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