# One rails, multiple DBs **URL:** \ **Category:** Rails\ **Created:** [February 10, 2010, 4:58pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248 "2010-02-10T16:58:35Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![arvias](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ac91a4/32.png) [@arvias](https://www.ruby-forum.com/u/arvias)\ **Post date:** [February 10, 2010, 4:58pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248/1 "2010-02-10T16:58:35Z")
Hi. I’m in a situation where I have to provide a hosted Rails App solution. I’m running Apache with passenger in the backend. What is the proper way to change the DB depending on the subdomain? Should I use data\_fabric? – R. ---
**Author:** ![arvias](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ac91a4/32.png) [@arvias](https://www.ruby-forum.com/u/arvias)\ **Post date:** [February 10, 2010, 5:05pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248/2 "2010-02-10T17:05:59Z")
Marcelo B. wrote: > Hi. > > I’m in a situation where I have to provide a hosted Rails App > solution. I’m running Apache with passenger in the backend. > > What is the proper way to change the DB depending on the subdomain? > Should I use data\_fabric? Generally, you don’t need a separate DB for each subdomain. One big DB is usually better. > – > R. Best, –Â Marnen Laibow-Koser [http://www.marnen.org](http://www.marnen.org) removed\_email\_address@domain.invalid ---
**Author:** ![arvias](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ac91a4/32.png) [@arvias](https://www.ruby-forum.com/u/arvias)\ **Post date:** [February 10, 2010, 7:00pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248/3 "2010-02-10T19:00:21Z")
Hi, > Generally, you don’t need a separate DB for each subdomain. One big DB > is usually better. It’s a high volume app, that’s written as a standalone service. Extending it as a hosted solution and keeping updates nice is a big part of what the project is about. – Cheers, M. ---
**Author:** ![arvias](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ac91a4/32.png) [@arvias](https://www.ruby-forum.com/u/arvias)\ **Post date:** [February 10, 2010, 7:02pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248/4 "2010-02-10T19:02:48Z")
Marcelo B. wrote: > Hi, > > > Generally, you don’t need a separate DB for each subdomain. �One big DB > > is usually better. > > It’s a high volume app, that’s written as a standalone service. > Extending it as a hosted solution and keeping updates nice is a big > part of what the project is about. And all of that would be easier with one big DB, at least as far as you’ve described. > – > Cheers, > M. Best, – Marnen Laibow-Koser [http://www.marnen.org](http://www.marnen.org) removed\_email\_address@domain.invalid ---
**Author:** ![arvias](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ac91a4/32.png) [@arvias](https://www.ruby-forum.com/u/arvias)\ **Post date:** [February 10, 2010, 7:35pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248/5 "2010-02-10T19:35:29Z")
Hi. > > It’s a high volume app, that’s written as a standalone service. > > Extending it as a hosted solution and keeping updates nice is a big > > part of what the project is about. > > And all of that would be easier with one big DB, at least as far as > you’ve described. You are right, it would definitely be easier if this App was written with a hosted version in mind. Unfortunately it isn’t. Still, the volume of traffic and DB size of the app means that if someone grows bigger we want to be able to quickly move it to something dedicated. – Cheers, R. ---
**Author:** ![arvias](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ac91a4/32.png) [@arvias](https://www.ruby-forum.com/u/arvias)\ **Post date:** [February 10, 2010, 7:52pm UTC](https://www.ruby-forum.com/t/one-rails-multiple-dbs/183248/6 "2010-02-10T19:52:27Z")
DataMapper out of the box will let you use multiple databases, although these need to be known at app boot time. For ActiveRecord, this article might lead you somewhere: [http://tomayko.com/writings/rails-multiple-connections](http://tomayko.com/writings/rails-multiple-connections) Nathan