[
https://issues.apache.org/jira/browse/SQOOP-1976?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14336040#comment-14336040
]
Qian Xu commented on SQOOP-1976:
--------------------------------
Return array means to create a defensive copy. As the method is called
extremely frequently, it will have performance impact. If create a copy as
array from an arraylist is cheap, I'm okay to close the jira. The comparison of
using array or arraylist is not the my concern. [~vybs] I assume you are
considering of immutability of data. Alternatively we can use Guava's
ImmutableList.
> Sqoop2: Avoid massive in-memory copy of schema column
> -----------------------------------------------------
>
> Key: SQOOP-1976
> URL: https://issues.apache.org/jira/browse/SQOOP-1976
> Project: Sqoop
> Issue Type: Sub-task
> Reporter: Qian Xu
> Assignee: Qian Xu
>
> SQOOP-1836 introduced a new method {{getColumnsArray}}. As the class
> {{Schema}} is used very often, the idea is to provide a constant (better)
> lookup time for particular column. But I think the implementation will create
> array from a list for every call, it will be even slower than accessing the
> original {{getColumnsList}} in some cases. I think we can change the type of
> columns from {{LinkedList}} to {{ArrayList}}, which is included in
> SQOOP-1969. The jira proposes to remove {{getColumnsArray}}.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
