factors on the effectiveness of bloom filter?

[Yang <te...@gmail.com>]

I noticed that 2 of my CFs are showing very different bloom filter
false ratios, one is close to 1.0;
the other one is only 0.3

they have roughly the same sizes in SStables and counts, the
difference is key construction,
the one with 0.3 false ratio has a shorter key.

assuming the key can not be changed (or the only possibility to change
they key is simply juggle the byte order),
is there any measure to increase the effectiveness of bloom filters?

thanks
Yang

Re: factors on the effectiveness of bloom filter?

[Radim Kolar <hs...@sendmail.cz>]

Dne 10.10.2011 18:31, Yang napsal(a):
> I noticed that 2 of my CFs are showing very different bloom filter
> false ratios, one is close to 1.0;
> the other one is only 0.3
cassandra bloom filters are computed for 1% false positive ratio.

is there any measure to increase the effectiveness of bloom filters? 
thanks Yang
try hadoop hbase. you can configure it there.