Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Accumulo >> mail # user >> Accumulo lexicographical order


Copy link to this message
-
Re: Accumulo lexicographical order
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.

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." <[EMAIL PROTECTED]>
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
>