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https://issues.apache.org/jira/browse/SQOOP-1968?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Qian Xu reassigned SQOOP-1968:
------------------------------
Assignee: Qian Xu
> 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
>
> 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.
> {quote}
> HashMap<String,Column> colNames = new HashMap<String, Column>();
> for (Column fromCol: getFromSchema().getColumnsArray()) {
> colNames.put(fromCol.getName(), fromCol);
> }
> {quote}
> 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
> {quote}
> int fromIndex = getFromSchema().getColumnsList().indexOf(fromCol);
> {quote}
> These performance problems are critical because getMatchingData is repeatedly
> calling for each record.
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