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From Jonathan Ellis <>
Subject Re: High BloomFilterFalseRation
Date Wed, 27 Oct 2010 13:58:17 GMT
This is not expected, no.  How random are your queries?  If you have a
couple outlier rows causing the false positives that are being queried
over and over then that could just be the luck of the draw.

On Wed, Oct 27, 2010 at 5:24 AM, Daniel Doubleday
<> wrote:
> Hi people
> We are currently moving our second use case from mysql to cassandra. While importing
the data (ongoing) I noticed that the BloomFilterFalseRation seems to be pretty high compared
to another CF which is in used in production right now.
> Its a hierarchical data model and I cannot avoid to do a read before inserting multiple
> I see a false positive ration of 0.28 while in my other CF it is 0.00025.
> The CF has 5 live sstables whiel I read that ratio. At that time I inserted ~ 200k rows
with a total of 1M cols. Row keys are pretty large unfortunately (key.length() ~ 60)
> Just wanted to check if this value is to be expected.
> Thanks,
> Daniel

Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support

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