Rails - Jan 2006 - Transactions with multiple databases

hi,
i have problem with transactions and multiple databases.

Object1 and Object2 are two different models/databases with different 
connections, when i use only
one model:

Object1.transaction do
   object1.value1 = "123456"
   object1.save
   do_some_error
end

it''s ok, error is produced, nothing is commited and database is
unchanged.

when i use 2 models, described  at
http://wiki.rubyonrails.com/rails/pages/HowToUseTransactions:

Object2.transaction do
   Object1.transaction do
     object1.value1 = "123456"
     object1.save
     do_some_error
   end
end

- error is produced, but object1 is commited and database is changed
- imho transaction is active(autocommit false) only for Object2 connection
- ruby-1.8.4, rails-1.0, dbriver is oci

any idea about this ?

thanks, peter

The Agile Book addresses just this situation and advises against using
ActiveRecord for updating multiple databases concurrently. What you are
doing is a simulation of a true multiple database transaction.


On 1/10/06, Petr Cervinka <petr.cervinka@gmail.com>
wrote:
>
> hi,
> i have problem with transactions and multiple databases.
>
> Object1 and Object2 are two different models/databases with different
> connections, when i use only
> one model:
>
> Object1.transaction do
>    object1.value1 = "123456"
>    object1.save
>    do_some_error
> end
>
> it''s ok, error is produced, nothing is commited and database is
unchanged.
>
> when i use 2 models, described  at
> http://wiki.rubyonrails.com/rails/pages/HowToUseTransactions:
>
> Object2.transaction do
>    Object1.transaction do
>      object1.value1 = "123456"
>      object1.save
>      do_some_error
>    end
> end
>
> - error is produced, but object1 is commited and database is changed
> - imho transaction is active(autocommit false) only for Object2 connection
> - ruby-1.8.4, rails-1.0, dbriver is oci
>
> any idea about this ?
>
> thanks, peter
>
>
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
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On 11/01/2006, at 5:40 AM, Petr Cervinka wrote:
> hi,
> i have problem with transactions and multiple databases.
For transactions across multiple databases to work right you need two- 
phase commit support. Rails doesn''t have two phase commit support, so  
even if it did work it wouldn''t do what you expect.


--
Phillip Hutchings
phillip.hutchings@sitharus.com