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https://issues.apache.org/jira/browse/SQOOP-1968?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14265926#comment-14265926
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Jarek Jarcec Cecho commented on SQOOP-1968:
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I'm generally +1 on the patch, I have two nits:
* Nit: There are unused imports in {{NameMatcher.java}}, can we remove them?
* In file {{SchemaFixture.java}} I would suggest to rename methods
{{createRandomSchema}} and {{createRandomSchema}} to not contain word "random"
as the schema doesn't seem to be randomized.
> Optimize schema operation in getMatchingData of NameMatcher
> -----------------------------------------------------------
>
> Key: SQOOP-1968
> URL: https://issues.apache.org/jira/browse/SQOOP-1968
> Project: Sqoop
> Issue Type: Improvement
> Components: connectors/generic
> Affects Versions: 2.0.0
> Reporter: Jerry Chen
> Assignee: Qian Xu
> Attachments: SQOOP-1968.patch
>
>
> Two performance issues found in the Matcher implementations.
> 1. In getMatchingData of NameMatcher, the following code block of building a
> HashMap will not change across different getMatchingData calls. The HashMap
> can build only once in Constructor.
> {code}
> HashMap<String,Column> colNames = new HashMap<String, Column>();
> for (Column fromCol: getFromSchema().getColumnsArray()) {
> colNames.put(fromCol.getName(), fromCol);
> }
> {code}
> 2. In getMatchingData of NameMatcher, indexOf of a List implementation is
> not efficient. It usually involves a loop for finding the object and return
> the index. To improve, we can simple store the index in the above HashMap and
> retrieve the index by HashMap lookup directly
> {code}
> int fromIndex = getFromSchema().getColumnsList().indexOf(fromCol);
> {code}
> These performance problems are critical because getMatchingData is repeatedly
> calling for each record.
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