Re: how to adjust auto increment id offset?

thanks a lot for the tip!

sorry for used the wrong word, it is just multi-master but not sharding, I
would like to setup two master server across two datacenter. one's id
increased by 1, and the other by 2.
so I could have a queue sync the record in the background by myself. kind
of a dumb way but it seems they only choice for me, the delay within
several minutes is acceptable.

On Tue, Nov 15, 2011 at 5:12 PM, John R Pierce <pierce(at)hogranch(dot)com> wrote:

> On 11/15/11 12:56 AM, Bèrto ëd Sèra wrote:
>
>> Hi
>>
>>
>> On 15 November 2011 11:44, Yan Chunlu <springrider(at)gmail(dot)com <mailto:
>> springrider(at)gmail(dot)com>**> wrote:
>>
>> I would like to implement two master db with even-odd id sharding.
>> in mysql it is fairly easy by using the configuration:
>>
>> auto_increment_offset = 1
>> auto_increment_increment = 2
>>
>>
>> but I have searched a lot didn't find anything related to this,
>> some users doing this via trigger like "rubyrep".
>>
>> is there an easy way to do this? thanks!
>>
>>
>> http://www.postgresql.org/**docs/8.1/static/sql-**createsequence.html<http://www.postgresql.org/docs/8.1/static/sql-createsequence.html>
>>
>>
>>
> also see ALTER SEQUENCE.
>
> basically, you'll need to fix up every sequence (these are created
> automatically if you have fields of type SERIAL).... on your 2nd server,
>
> ALTER SEQUENCE somesequencename INCREMENT BY 2 RESTART WITH 2;
>
> and on your 1st server,
>
> ALTER SEQUENCE somesequencename INCREMENT BY 2;
>
> do this before inserting any data.
>
> thats a fairly unusual sharding technique, how do you plan on doing
> queries across both sets of data?
>
>
> --
> john r pierce N 37, W 122
> santa cruz ca mid-left coast
>
>
>
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