sequence number

[Noureddine BOUYAHIAOUI <no...@free.fr>]

Hi,

In my reads about HBase, I understand that, The HRegionServer (n time
HRegion) use sequence number ( AtomicLong ) to version each key/value
stored in WAL.

Please can you give me some details about this notion, for example how
HRegionServer create his sequence number, and why we use it. Is't
considered as version identifier?

Best regards.

Noureddine Bouyahiaoui

Re: sequence number

[N Keywal <nk...@gmail.com>]

Hi,

Yes, each cell is associated to a long. By default it's a timestamps, but
you can set it yourself when you create the put.
It's stored everywhere.

You've got a lot of information and links on this in the hbase book (
http://hbase.apache.org/book.html#versions)

Cheers,

N.

On Mon, Jan 30, 2012 at 9:38 PM, Noureddine BOUYAHIAOUI <
nour.bouyahiaoui@free.fr> wrote:

> Hi,
>
> In my reads about HBase, I understand that, The HRegionServer (n time
> HRegion) use sequence number ( AtomicLong ) to version each key/value
> stored in WAL.
>
> Please can you give me some details about this notion, for example how
> HRegionServer create his sequence number, and why we use it. Is't
> considered as version identifier?
>
> Best regards.
>
> Noureddine Bouyahiaoui
>
>
>
>