1 files changed, 10 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index cfff7202a3..ba1cb05d2c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -95,8 +95,6 @@ module ActiveRecord
         @last_use            = false
         @logger              = logger
         @pool                = pool
-        @query_cache         = Hash.new { |h,sql| h[sql] = {} }
-        @query_cache_enabled = false
         @schema_cache        = SchemaCache.new self
         @visitor             = nil
       end
@@ -293,6 +291,14 @@ module ActiveRecord
         false
       end
 
+      # This is meant to be implemented by the adapters that support extensions
+      def disable_extension(name)
+      end
+
+      # This is meant to be implemented by the adapters that support extensions
+      def enable_extension(name)
+      end
+
       # A list of extensions, to be filled in by adapters that support them. At
       # the moment only postgresql does.
       def extensions
@@ -307,8 +313,8 @@ module ActiveRecord
 
       # QUOTING ==================================================
 
-      # Returns a bind substitution value given a +column+ and list of current
-      # +binds+.
+      # Returns a bind substitution value given a bind +index+ and +column+
+      # NOTE: The column param is currently being used by the sqlserver-adapter
       def substitute_at(column, index)
         Arel::Nodes::BindParam.new '?'
       end