Rails Lighthouse ticket #1533

0001-broke-out-joining-the-quoted-values-in-activerecord.patch

From 328011d9841b0d4999878b582e50a6e9489a5ae5 Mon Sep 17 00:00:00 2001
From: Nathan Zook <blogger@pierian-spring.net>
Date: Thu, 4 Mar 2010 17:14:19 -0600
Subject: [PATCH] Broke out joining the quoted values in ActiveRecord::Base (to support the Oracle adapter)

---
 activerecord/lib/active_record/base.rb |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index cd67490..68dec91 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1639,13 +1639,17 @@ module ActiveRecord #:nodoc:
             if value.respond_to?(:empty?) && value.empty?
               connection.quote(nil)
             else
-              value.map { |v| connection.quote(v) }.join(',')
+              join_quoted_values_for_condition(value.map{|v| connection.quote(v)})
             end
           else
             connection.quote(value)
           end
         end
 
+        def join_quoted_values_for_condition(values) #:nodoc:
+          values * ','
+        end
+
         def raise_if_bind_arity_mismatch(statement, expected, provided) #:nodoc:
           unless expected == provided
             raise PreparedStatementInvalid, "wrong number of bind variables (#{provided} for #{expected}) in: #{statement}"
-- 
1.6.0.4

commit-3e79b5f

commit 3e79b5f92602051b47f9d20cedf51dd96ff93b82
Author: Giorgio Gonnella <ggonnell@yahoo.it>
Date:   Mon Mar 2 17:44:41 2009 +0100

    Solves preloading more than 1000 associated records in Oracle
    
    Rails often uses "in" sql clauses when preloading associations. Oracle has 
    a 1000 term restriction on such clauses, so that you cannot say something 
    like "WHERE parent_id IN (1,2,3,4 ... 1001)".
    
    [#1533 state:resolved] 

diff --git a/vendor/rails/activerecord/lib/active_record/association_preload.rb b/vendor/rails/activerecord/lib/active_record/association_preload.rb
index 69300e5..4ecad6f 100644
--- a/vendor/rails/activerecord/lib/active_record/association_preload.rb
+++ b/vendor/rails/activerecord/lib/active_record/association_preload.rb
@@ -322,8 +322,9 @@ module ActiveRecord
             end
           end
           conditions = "#{table_name}.#{connection.quote_column_name(primary_key)} #{in_or_equals_for_ids(ids)}"
+          conditions = ([conditions] * (ids.size.to_f/1000).ceil).join(" OR ")
           conditions << append_conditions(reflection, preload_options)
-          associated_records = klass.find(:all, :conditions => [conditions, ids],
+          associated_records = klass.find(:all, :conditions => [conditions, *ids.in_groups_of(1000, false)],
                                           :include => options[:include],
                                           :select => options[:select],
                                           :joins => options[:joins],
@@ -335,20 +336,21 @@ module ActiveRecord
       def find_associated_records(ids, reflection, preload_options)
         options = reflection.options
         table_name = reflection.klass.quoted_table_name
-
+        
         if interface = reflection.options[:as]
           conditions = "#{reflection.klass.quoted_table_name}.#{connection.quote_column_name "#{interface}_id"} #{in_or_equals_for_ids(ids)} and #{reflection.klass.quoted_table_name}.#{connection.quote_column_name "#{interface}_type"} = '#{self.base_class.sti_name}'"
         else
           foreign_key = reflection.primary_key_name
           conditions = "#{reflection.klass.quoted_table_name}.#{foreign_key} #{in_or_equals_for_ids(ids)}"
         end
-
+        
+        conditions = ([conditions] * (ids.size.to_f/1000).ceil).join(" OR ")
         conditions << append_conditions(reflection, preload_options)
-
+        
         reflection.klass.find(:all,
                               :select => (preload_options[:select] || options[:select] || "#{table_name}.*"),
                               :include => preload_options[:include] || options[:include],
-                              :conditions => [conditions, ids],
+                              :conditions => [conditions, *ids.in_groups_of(1000, false)],
                               :joins => options[:joins],
                               :group => preload_options[:group] || options[:group],
                               :order => preload_options[:order] || options[:order])

oracle_association_limit_bug.rb

# Ugly monkey patch so Rails can load associations with more than 1000 items in
# Oracle. See: https://rails.lighthouseapp.com/projects/8994/tickets/1533
module ActiveRecord
  module AssociationPreloadOracleWorkaround
    # Oracle's IN() clause limit.
    ORACLE_LIMIT = 1000

    # Oracle's limit on number of arguments to a function.
    ORACLE_CHUNK = 255

    def self.included(base)
      base.extend(ClassMethods)
      base.class_eval do
        class << self
          alias_method_chain(:in_or_equals_for_ids, :oracle_workaround)
        end
      end
    end

    module ClassMethods
      # Override in_or_equals_for_ids to split IN clauses that have more than
      # 1000 items in them.
      def in_or_equals_for_ids_with_oracle_workaround(ids)
        sql = ""

        if(ids.size > ORACLE_LIMIT)
          # If there are more than 1000, actually separate them into groups of
          # 255, since that seems to be the limit of Oracle's odcinumberlist().
          in_clauses = []
          0.step(ids.size, ORACLE_CHUNK) do |i|
            ids_chunk = ids[i, ORACLE_CHUNK]
            in_clauses << sanitize_sql_array(["(SELECT * FROM TABLE(sys.odcinumberlist(?)))", ids_chunk])
          end

          sql = "IN(#{in_clauses.join(" UNION ")})"
        else
          sql = in_or_equals_for_ids_without_oracle_workaround(ids)
        end

        sql
      end
    end
  end
end

ActiveRecord::Base.send :include, ActiveRecord::AssociationPreloadOracleWorkaround