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HBase >> mail # user >> Re: row filter - binary comparator at certain range


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Tony Duan 2013-10-21, 04:31
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Michael Segel 2013-10-21, 11:36
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Michael Segel 2013-10-21, 11:38
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Premal Shah 2013-10-21, 05:42
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James Taylor 2013-10-21, 06:05
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Vladimir Rodionov 2013-10-21, 16:14
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James Taylor 2013-10-21, 16:37
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Re: row filter - binary comparator at certain range
Then its not a SALT. And please don't use the term 'salt' because it has specific meaning outside to what you want it to mean.  Just like saying HBase has ACID because you write the entire row as an atomic element.  But I digress….

Ok so to your point…

1 byte == 255 possible values.

So which will be faster.

creating a list of the 1 byte truncated hash of each possible timestamp in your range, or doing 255 separate range scans with the start and stop range key set?

That will give you the results you want, however… I'd go back and have them possibly rethink the row key if they can … assuming this is the base access pattern.

HTH

-Mike

On Oct 21, 2013, at 11:37 AM, James Taylor <[EMAIL PROTECTED]> wrote:

> Phoenix restricts salting to a single byte.
> Salting perhaps is misnamed, as the salt byte is a stable hash based on the
> row key.
> Phoenix's skip scan supports sub-key ranges.
> We've found salting in general to be faster (though there are cases where
> it's not), as it ensures better parallelization.
>
> Regards,
> James
>
>
>
> On Mon, Oct 21, 2013 at 9:14 AM, Vladimir Rodionov
> <[EMAIL PROTECTED]>wrote:
>
>> FuzzyRowFilter does not work on sub-key ranges.
>> Salting is bad for any scan operation, unfortunately. When salt prefix
>> cardinality is small (1-2 bytes),
>> one can try something similar to FuzzyRowFilter but with additional
>> sub-key range support.
>> If salt prefix cardinality is high (> 2 bytes) - do a full scan with your
>> own Filter (for timestamp ranges).
>>
>> Best regards,
>> Vladimir Rodionov
>> Principal Platform Engineer
>> Carrier IQ, www.carrieriq.com
>> e-mail: [EMAIL PROTECTED]
>>
>> ________________________________________
>> From: Premal Shah [[EMAIL PROTECTED]]
>> Sent: Sunday, October 20, 2013 10:42 PM
>> To: user
>> Subject: Re: row filter - binary comparator at certain range
>>
>> Have you looked at FuzzyRowFilter? Seems to me that it might satisfy your
>> use-case.
>>
>> http://blog.sematext.com/2012/08/09/consider-using-fuzzyrowfilter-when-in-need-for-secondary-indexes-in-hbase/
>>
>>
>> On Sun, Oct 20, 2013 at 9:31 PM, Tony Duan <[EMAIL PROTECTED]> wrote:
>>
>>> Alex Vasilenko <aa.vasilenko@...> writes:
>>>
>>>>
>>>> Lars,
>>>>
>>>> But how it will behave, when I have salt at the beginning of the key to
>>>> properly shard table across regions? Imagine row key of format
>>>> salt:timestamp and rows goes like this:
>>>> ...
>>>> 1:15
>>>> 1:16
>>>> 1:17
>>>> 1:23
>>>> 2:3
>>>> 2:5
>>>> 2:12
>>>> 2:15
>>>> 2:19
>>>> 2:25
>>>> ...
>>>>
>>>> And I want to find all rows, that has second part (timestamp) in range
>>>> 15-25. What startKey and endKey should be used?
>>>>
>>>> Alexandr Vasilenko
>>>> Web Developer
>>>> Skype:menterr
>>>> mob: +38097-611-45-99
>>>>
>>>> 2012/2/9 lars hofhansl <lhofhansl@...>
>>> Hi,
>>> Alexandr Vasilenko
>>> Have you ever resolved this issue?i am also facing this iusse.
>>> i also want implement this functionality.
>>> Imagine row key of format
>>> salt:timestamp and rows goes like this:
>>> ...
>>> 1:15
>>> 1:16
>>> 1:17
>>> 1:23
>>> 2:3
>>> 2:5
>>> 2:12
>>> 2:15
>>> 2:19
>>> 2:25
>>> ...
>>>
>>> And I want to find all rows, that has second part (timestamp) in range
>>> 15-25.
>>>
>>> Could you please tell me how you resolve this ?
>>> thanks  in advance.
>>>
>>>
>>> Tony duan
>>>
>>>
>>
>>
>> --
>> Regards,
>> Premal Shah.
>>
>> Confidentiality Notice:  The information contained in this message,
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James Taylor 2013-10-21, 20:26
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Michael Segel 2013-10-21, 20:48
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James Taylor 2013-10-21, 22:07
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Michael Segel 2013-10-22, 00:58
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James Taylor 2013-10-22, 03:54
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Asaf Mesika 2013-11-01, 07:25
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Vladimir Rodionov 2013-10-21, 16:50
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Vladimir Rodionov 2013-10-21, 16:36
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Tony Duan 2013-10-22, 07:55
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB