set_table_name woes, fragmented domain class

rubyonrails-talk
1

Hi all,

I'm running Rails on top of a Mongrel cluster. I have several model classes that are going to have so many records it is not feasible to keep them all in the same table. So I've split out the records into many different tables, each with its own suffix which corresponds to the id of the model to which all records in that particular table belong.

For example, if I have a Domain AR object with an id of 20, all DomainURL objects that :belong_to that particular Domain object are stored in table domain_urls_20.

This necessitates a call to set_table_name before the DomainURL objects are fetched, like so:

DomainURL.set_table_name "domain_urls_" + domain.id

However, when I go into production mode, I get mismatched table and column names on my find's. I am assuming this is caused by ActiveRecord caching the domain model so that set_table_name is rendered ineffective when it goes to fetch a record. However, I'm not quite sure if this is the case.

If anyone could shed some light here, or possibly suggest an alternative method of accomplishing my objective, I'm all ears.

Thanks,

Michael J. I. Jackson mjijackson@gmail.com

2

Michael J. I. Jackson wrote:

I'm running Rails on top of a Mongrel cluster. I have several model classes that are going to have so many records it is not feasible to keep them all in the same table. So I've split out the records into many different tables, each with its own suffix which corresponds to the id of the model to which all records in that particular table belong.

For example, if I have a Domain AR object with an id of 20, all DomainURL objects that :belong_to that particular Domain object are stored in table domain_urls_20.

This necessitates a call to set_table_name before the DomainURL objects are fetched, like so:

DomainURL.set_table_name "domain_urls_" + domain.id

However, when I go into production mode, I get mismatched table and column names on my find's. I am assuming this is caused by ActiveRecord caching the domain model so that set_table_name is rendered ineffective when it goes to fetch a record. However, I'm not quite sure if this is the case.

Perhaps your problem is caching of table names by the urls association. You could clear the cache using something like

class Domain    has_many :urls, :class_name => 'DomainURL'

   def set_url_table      self.class.reflect_on_association(:urls).instance_eval do        @table_name = @quoted_table_name = nil      end      DomainURL.set_table_name "domain_urls_" + id    end end

domain = Domain.find(...) domain.set_url_table urls = domain.urls