Re: [Postgres-xc-general] Primary Key Conflict

[Gilberto N. <gil...@gm...>]

So, in other words, I will have this on the clients ( nodes ) and not on
the central DB ( coordinators ).
Sorry if I do not understand cleary what you explain... I am really new in
DB world...


2014-10-08 10:12 GMT-03:00 Michael Paquier <mic...@gm...>:

>
>
> On Wed, Oct 8, 2014 at 9:36 PM, Gilberto Nunes <gil...@gm...
> > wrote:
>
>> Let say if I have two store and the DB is deploy under postgres-xc. Now
>> Store A, record a register like 00010, and Store B record a register like
>> 00010 two.
>> And both sites write this locally and in a center DB with postgres-xc
>> too, of course...
>> How postgres-xc will handle with this? Or I will need create differents
>> ID for both Store like A00010, for Store A, and B00010, fo Store B.
>>
> Note the definition of constraints is strictly related to the distribution
> of the table they are defined on. For example, in the case of hash tables,
> primary keys and unique constraints need absolutely to contain the column
> sharded. For replicated tables, there is no real restriction, at the cost
> that each write needs to be done with 2PC on all the nodes. Btw, what I
> meant in this explanation is something that you have perhaps already
> guessed: constraint definition restriction is here because XC guarantees
> only constraint checks on the datanodes, and not on coordinators.
> --
> Michael
>



-- 
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Gilberto Ferreira