Clear query cache during checkin, instead of an execution callback

It doesn't make sense for the query cache to persist while a connection
moves through the pool and is assigned to a new thread.

[Samuel Cochran & Matthew Draper]

1 files changed, 2 insertions, 9 deletions

diff --git a/activerecord/lib/active_record/query_cache.rb b/activerecord/lib/active_record/query_cache.rb
index c42c22ab09..23dae825c2 100644
--- a/activerecord/lib/active_record/query_cache.rb
+++ b/activerecord/lib/active_record/query_cache.rb
@@ -24,17 +24,10 @@ module ActiveRecord
     end
 
     def self.run
-      connection    = ActiveRecord::Base.connection
-      enabled       = connection.query_cache_enabled
-      connection.enable_query_cache!
-
-      [connection, enabled]
+      ActiveRecord::Base.connection.enable_query_cache!
     end
 
-    def self.complete((connection, enabled))
-      connection.clear_query_cache
-      connection.disable_query_cache! unless enabled
-
+    def self.complete(_)
       unless ActiveRecord::Base.connected? && ActiveRecord::Base.connection.transaction_open?
         ActiveRecord::Base.clear_active_connections!
       end