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From William Slacum <>
Subject Re: Performance of table with large number of column families
Date Fri, 09 Nov 2012 16:41:15 GMT
I guess assuming you have 10M possible partitions, if you're using a
relatively uniform hash to generate your IDs, you'll average about 2 per
partition. Do you have any index for term/value to partition? This will
help you narrow down your search space to a subset of your partitions.

On Fri, Nov 9, 2012 at 11:39 AM, William Slacum <> wrote:

> That shouldn't be a huge issue. How many rows/partitions do you have? How
> many do you have to scan to find the specific column family/doc id you want?
> On Fri, Nov 9, 2012 at 11:26 AM, Anthony Fox <> wrote:
>> I have a table set up to use the intersecting iterator pattern.  The
>> table has about 20M records which leads to 20M column families for the
>> data section - 1 unique column family per record.  The index section of
>> the table is not quite as large as the data section.  The rowkey is a
>> random padded integer partition between 0000000 and 9999999.  I turned
>> bloom filters on and used the ColumnFamilyFunctor to get performant
>> column family scans without specifying a range like in the bloom filter
>> examples in the README.  However, my column family scans (without any
>> custom iterator) are still fairly slow - ~30 seconds for a column family
>> batch scan of one record. I've also tried RowFunctor but I see similar
>> performance.  Can anyone shed any light on the performance metrics I'm
>> seeing?
>> Thanks,
>> Anthony

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