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From Joost Ouwerkerk <jo...@openplaces.org>
Subject Single Split ColumnFamilyRecordReader returns duplicate rows
Date Fri, 30 Apr 2010 21:55:55 GMT
There's a bug in ColumnFamilyRecordReader that appears when processing
a single split.  When the start and end tokens of the split are equal,
duplicate rows can be returned.

Example with 5 rows:
token (start and end) = 53193025635115934196771903670925341736

Tokens returned by first get_range_slices iteration:
 16955237001963240173058271559858726497
 40670782773005619916245995581909898190
 99079589977253916124855502156832923443
 144992942750327304334463589818972416113
 166860289390734216023086131251507064403

Tokens returned by next iteration (first token is last token from
previous, end token is unchanged)
 16955237001963240173058271559858726497
 40670782773005619916245995581909898190

Tokens returned by final iteration  (first token is last token from
previous, end token is unchanged)
 [] (empty)

In this example, the mapper has processed 7 rows in total, 2 of which
were duplicates.

Joost.

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