Rails - Apr 2009 - Does rake db:migrate protect against concurrent use?

If two people go to the same rails application (same directory) and
both run "rake db:migrate" to update the database with a set of
migrations (the same ones) at the same time, is it likely that bad
things will happen to the data, or will db:migrate do something to
prevent the same migration from being run by more than one
(simultaneous) process?

Thanks,
   --Paul
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

> If two people go to the same rails application (same directory) and
> both run "rake db:migrate" to update the database with a set of
> migrations (the same ones) at the same time, is it likely that bad
> things will happen to the data, or will db:migrate do something to
> prevent the same migration from being run by more than one
> (simultaneous) process?
rake db:migrate is only tuned for one development workstation.

Are you implying your developers don''t have individual databases?

In my experience running various rake commands accidentally at the same 
time, one batch will "win", and the other will cough up a zillion
errors and
expire gracelessly... 




--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Depending on your DB, it may support transactional migrations (as of
Rails 2.2). That should ensure that only one set of changes go
through. Haven''t ever tried it, but it should probably work.

--Matt Jones


On Apr 16, 6:47 pm, "Phlip"
<phlip2...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> > If two people go to the same rails application (same directory) and
> > both run "rake db:migrate" to update the database with a set
of
> > migrations (the same ones) at the same time, is it likely that bad
> > things will happen to the data, or will db:migrate do something to
> > prevent the same migration from being run by more than one
> > (simultaneous) process?
>
> rake db:migrate is only tuned for one development workstation.
>
> Are you implying your developers don''t have individual databases?
>
> In my experience running various rake commands accidentally at the same
> time, one batch will "win", and the other will cough up a zillion
errors and
> expire gracelessly...
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---