> 1) What is the ratio of the sstable file size to bloom filter size ? If i
> have a sstable of 1 GB, what is the approximate bloom filter size ? Assuming
> 0.000744 default val configured.
The size of the bloom filter varies with the number of rows in the CF, not the
on disk size. More correctly
More insight for this sstable: the ArrayList for IndexSummary has 644195
entries, so total number of entries for this sstable is: 644195*128=~82mil.
The problem is that the total bits for its BloomFilter (long[19400551]
inside BitSet) is 19400551*64=1241635264, which means each key is taking
~15bit
BloomFilter is not redundant, because it stores information about
_all_ keys while the index summary stores every 1/128 key.
On Tue, May 4, 2010 at 3:47 PM, Weijun Li wrote:
> Hello,
>
> We stored about 47mil keys in one Cassandra node and what a memory dump
> shows for one of the SStableReader:
