accumulo-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Keith Turner <ke...@deenlo.com>
Subject Re: Accumulo lexicographical order
Date Wed, 08 Jan 2014 17:03:52 GMT
On Wed, Jan 8, 2014 at 11:50 AM, Mike Drob <mdrob@mdrob.com> wrote:

> Duane,
>
> Most API methods for inserting values take byte arrays or byte sequences
> directly. The lexographic order is based on the natural ordering of the
> bytes, i.e. \x00 sorts before \x01. The methods that take strings will
> assume UTF-8 encoding and convert for you. If you find a situation where
> this is not the case, please let us know!
>
> The one exception to all of this is the timestamp part of the key, which
> is stored in numeric order. I want to say that they are kept in reverse
> order, but don't remember the exact details off hand.
>
Thats correct.  The most recent timestamps are sorted first.  Sorted as
signed long.



> I'm on my phone, so finding the exact place where this is documented will
> be a challenge, but I would expect it to be part of our user manual on
> accumulo.apache.org
>
> Mike
> On Jan 8, 2014 8:26 AM, "Cornish, Duane C." <Duane.Cornish@jhuapl.edu>
> wrote:
>
>> Accumulo Users,
>>
>>
>>
>> I know Accumulo keys are sorted in lexicographical order in the tables.
>> Where can I find the specification defining that order?  For example, what
>> lexicographical order are symbols in?  Is the order the same as the
>> numerical order of UTF-8 encoding, ASCII encoding, or some other encoding
>> scheme?
>>
>>
>>
>> Thanks in advance,
>>
>> Duane Cornish
>>
>

Mime
View raw message