`Connection#structure_dump` is no longer used. #9518

As of ccc6910c we use `mysqldump` to create the `structure.sql`.
The old `#structure_dump` code is still in AR but never used.

I removed all relevant parts from the code-base.

activerecord/CHANGELOG.md

 ## Rails 4.0.0 (unreleased) ##
 
+*   Remove `connection#structure_dump`, which is no longer used. *Yves Senn*
+
 *   Make it possible to execute migrations without a transaction even
     if the database adapter supports DDL transactions.
     Fixes #9483.

activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

@@ -516,11 +516,6 @@ def remove_reference(table_name, ref_name, options = {})
       end
       alias :remove_belongs_to :remove_reference
 
-      # Returns a string of <tt>CREATE TABLE</tt> SQL statement(s) for recreating the
-      # entire structure of the database.
-      def structure_dump
-      end
-
       def dump_schema_information #:nodoc:
         sm_table = ActiveRecord::Migrator.schema_migrations_table_name
 

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -332,20 +332,6 @@ def empty_insert_statement_value
 
       # SCHEMA STATEMENTS ========================================
 
-      def structure_dump #:nodoc:
-        if supports_views?
-          sql = "SHOW FULL TABLES WHERE Table_type = 'BASE TABLE'"
-        else
-          sql = "SHOW TABLES"
-        end
-
-        select_all(sql, 'SCHEMA').map { |table|
-          table.delete('Table_type')
-          sql = "SHOW CREATE TABLE #{quote_table_name(table.to_a.first.last)}"
-          exec_query(sql, 'SCHEMA').first['Create Table'] + ";\n\n"
-        }.join
-      end
-
       # Drops the database specified on the +name+ attribute
       # and creates it again using the provided +options+.
       def recreate_database(name, options = {})

activerecord/test/cases/adapters/mysql/reserved_word_test.rb

@@ -63,11 +63,6 @@ def test_change_columns
     assert_nothing_raised { @connection.rename_column(:group, :order, :values) }
   end
 
-  # dump structure of table with reserved word name
-  def test_structure_dump
-    assert_nothing_raised { @connection.structure_dump  }
-  end
-
   # introspect table with reserved word name
   def test_introspect
     assert_nothing_raised { @connection.columns(:group) }

activerecord/test/cases/adapters/mysql2/connection_test.rb

@@ -70,12 +70,6 @@ def test_mysql_set_session_variable_to_default
     end
   end
 
-  def test_logs_name_structure_dump
-    @connection.structure_dump
-    assert_equal "SCHEMA", @connection.logged[0][1]
-    assert_equal "SCHEMA", @connection.logged[2][1]
-  end
-
   def test_logs_name_show_variable
     @connection.show_variable 'foo'
     assert_equal "SCHEMA", @connection.logged[0][1]

activerecord/test/cases/adapters/mysql2/reserved_word_test.rb

@@ -63,11 +63,6 @@ def test_change_columns
     assert_nothing_raised { @connection.rename_column(:group, :order, :values) }
   end
 
-  # dump structure of table with reserved word name
-  def test_structure_dump
-    assert_nothing_raised { @connection.structure_dump  }
-  end
-
   # introspect table with reserved word name
   def test_introspect
     assert_nothing_raised { @connection.columns(:group) }