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From Vladimir Rodionov <vrodio...@carrieriq.com>
Subject skipKVsNewerThanReadpoint in StoreFileScanner and MemStoreScanner
Date Fri, 11 Oct 2013 21:18:45 GMT
>From HRegion:

synchronized(scannerReadPoints) {
        if (isolationLevel == IsolationLevel.READ_UNCOMMITTED) {
          // This scan can read even uncommitted transactions
          this.readPt = Long.MAX_VALUE;
        } else {
          this.readPt = MultiVersionConsistencyControl.resetThreadReadPoint(mvcc);

If isolation level is READ_UNCOMMITTED than this method should never be called in both StoreFileScanner
and MemStoreScanner
If isolation level is READ_COMMITTED than this method must be called only in MemStoreScanner,
because HFiles are immutable no new KV's can be added
to HFile after StoreFileScanner was created.


Best regards,
Vladimir Rodionov
Principal Platform Engineer
Carrier IQ, www.carrieriq.com
e-mail: vrodionov@carrieriq.com

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