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Andrew Purtell commented on HBASE-3855: --------------------------------------- If this is an 0.90 branch only issue then I suggest we can just leave this open without a target fix version and change the title to be "[0.90 branch] ...". Someone can pick it up and push it through to completion if they find it compelling. > Performance degradation of memstore because reseek is linear > ------------------------------------------------------------ > > Key: HBASE-3855 > URL: https://issues.apache.org/jira/browse/HBASE-3855 > Project: HBase > Issue Type: Improvement > Reporter: dhruba borthakur > Priority: Critical > Fix For: 0.90.7 > > Attachments: memstoreReseek.txt, memstoreReseek2.txt > > > The scanner use reseek to find the next row (or next column) as part of a > scan. The reseek code iterates over a Set to position itself at the right > place. If there are many thousands of kvs that need to be skipped over, then > the time-cost is very high. In this case, a seek would be far lesser in cost > than a reseek. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira