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From "Hiller, Dean" <>
Subject map/reduce performance time and sstable readerĊ .
Date Fri, 30 Aug 2013 13:25:09 GMT
Has anyone done performance tests on sstable reading vs. M/R?  I did a quick test on reading
all SSTAbles in a LCS column family on 23 tables and took the average time it took sstable2json(to
/dev/null to make it faster) which was 7 seconds per table.  (reading to stdout took 16 seconds
per table).  This then worked out to an estimation of 12.5 hours up to 27 hours(from to stdout
calculation).  I am suspecting the map/reduce time may be much worse since there are not as
many repeated rows in LCS????

Ie. I am wondering if I should just read from SSTAbles directly instead of map/reduce?   I
am about to dig around in the code of M/R and sstable2json to see what each is doing specifically.


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