Reduce the calling `create_table_info` query

Currently in schema dumping, `create_table_info` query is called twice
for each tables. It means if 100 tables exists, the query is called 200
times. This change is that the query is called once for each tables in
schema dumping.

1 files changed, 7 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 7b47539596..fbfc09e801 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -685,7 +685,7 @@ module ActiveRecord
             AND fk.table_name = '#{table_name}'
         SQL
 
-        create_table_info = select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
+        create_table_info = create_table_info(table_name)
 
         fk_info.map do |row|
           options = {
@@ -702,7 +702,7 @@ module ActiveRecord
       end
 
       def table_options(table_name)
-        create_table_info = select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
+        create_table_info = create_table_info(table_name)
 
         # strip create_definitions and partition_options
         raw_table_options = create_table_info.sub(/\A.*\n\) /m, '').sub(/\n\/\*!.*\*\/\n\z/m, '').strip
@@ -1018,6 +1018,11 @@ module ActiveRecord
         end
       end
 
+      def create_table_info(table_name) # :nodoc:
+        @create_table_info_cache = {}
+        @create_table_info_cache[table_name] ||= select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
+      end
+
       def create_table_definition(name, temporary = false, options = nil, as = nil) # :nodoc:
         TableDefinition.new(native_database_types, name, temporary, options, as)
       end