jojochuang commented on a change in pull request #3562: URL: https://github.com/apache/hbase/pull/3562#discussion_r684142758
########## File path: hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/mapreduce/MapReduceBackupCopyJob.java ########## @@ -331,12 +331,12 @@ protected Path createInputFileListing(Job job) throws IOException { private Text getKey(Path path) { int level = conf.getInt(NUMBER_OF_LEVELS_TO_PRESERVE_KEY, 1); int count = 0; - String relPath = ""; + StringBuilder relPath = new StringBuilder(); Review comment: It's not that obvious to me that using StringBuilder in this way is faster (looking at the jira, I assumed this is the purpose of the change) than simple string concatenation, because StringBuilder.insert() may involve multiple array copy. How about instantiating StringBuilder with a capacity (=level) as parameter so that we don't need to re-allocate & copy arrays? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@hbase.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org