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Hadoop QA commented on HDFS-7174: --------------------------------- \\ \\ | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:red}-1{color} | patch | 0m 0s | The patch command could not apply the patch during dryrun. | \\ \\ || Subsystem || Report/Notes || | Patch URL | http://issues.apache.org/jira/secure/attachment/12672576/HDFS-7174.new.patch | | Optional Tests | javadoc javac unit findbugs checkstyle | | git revision | trunk / f1a152c | | Console output | https://builds.apache.org/job/PreCommit-HDFS-Build/10676/console | This message was automatically generated. > Support for more efficient large directories > -------------------------------------------- > > Key: HDFS-7174 > URL: https://issues.apache.org/jira/browse/HDFS-7174 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: Kihwal Lee > Assignee: Kihwal Lee > Priority: Critical > Attachments: HDFS-7174.new.patch, HDFS-7174.patch, HDFS-7174.patch > > > When the number of children under a directory grows very large, insertion > becomes very costly. E.g. creating 1M entries takes 10s of minutes. This is > because the complexity of an insertion is O\(n\). As the size of a list > grows, the overhead grows n^2. (integral of linear function). It also causes > allocations and copies of big arrays. -- This message was sent by Atlassian JIRA (v6.3.4#6332)