Custom index type support with :using.

4 files changed, 31 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index b358d84365..2f17e47b7c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -8,7 +8,7 @@ module ActiveRecord
     # Abstract representation of an index definition on a table. Instances of
     # this type are typically created and returned by methods in database
     # adapters. e.g. ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter#indexes
-    class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where) #:nodoc:
+    class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where, :using) #:nodoc:
     end
 
     # Abstract representation of a column definition. Instances of this type
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index a26a0b54ea..26cacbde37 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -497,7 +497,14 @@ module ActiveRecord
       #
       #   CREATE UNIQUE INDEX index_accounts_on_branch_id_and_party_id ON accounts(branch_id, party_id) WHERE active
       #
-      # Note: only supported by PostgreSQL.
+      # ====== Creating an index with a specific method
+      #  add_index(:developers, :name, :using => 'btree')
+      # generates
+      #  CREATE INDEX index_developers_on_name ON developers USING btree (name) -- PostgreSQL
+      #  CREATE INDEX index_developers_on_name USING btree ON developers (name) -- MySQL
+      #
+      # Note: only supported by PostgreSQL and MySQL
+      #
       def add_index(table_name, column_name, options = {})
         index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
         execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options}"
@@ -745,7 +752,7 @@ module ActiveRecord
           index_name   = index_name(table_name, column: column_names)
 
           if Hash === options # legacy support, since this param was a string
-            options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal)
+            options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using)
 
             index_type = options[:unique] ? "UNIQUE" : ""
             index_name = options[:name].to_s if options.key?(:name)
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 b1baf24cb6..1f111a0976 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -432,6 +432,7 @@ module ActiveRecord
               next if row[:Key_name] == 'PRIMARY' # skip the primary key
               current_index = row[:Key_name]
               indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique].to_i == 0, [], [])
+              indexes.last.using = row[:Index_type].downcase.to_sym
             end
 
             indexes.last.columns << row[:Column_name]
@@ -504,6 +505,15 @@ module ActiveRecord
         rename_column_indexes(table_name, column_name, new_column_name)
       end
 
+      def add_index(table_name, column_name, options = {}) #:nodoc:
+        if options.is_a?(Hash) && options[:using]
+          index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
+          execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} USING #{options[:using]} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options}"
+        else
+          super
+        end
+      end
+
       # Maps logical Rails types to MySQL-specific data types.
       def type_to_sql(type, limit = nil, precision = nil, scale = nil)
         case type.to_s
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 0622d0a909..688bf1774b 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -160,8 +160,9 @@ module ActiveRecord
             desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
             orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
             where = inddef.scan(/WHERE (.+)$/).flatten[0]
+            type = inddef.scan(/USING (.+?) /).flatten[0].to_sym
 
-            column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where)
+            column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, type)
           end.compact
         end
 
@@ -408,6 +409,15 @@ module ActiveRecord
           rename_column_indexes(table_name, column_name, new_column_name)
         end
 
+        def add_index(table_name, column_name, options = {}) #:nodoc:
+          if options.is_a?(Hash) && options[:using]
+            index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
+            execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} USING #{options[:using]} (#{index_columns})#{index_options}"
+          else
+             super
+          end
+        end
+
         def remove_index!(table_name, index_name) #:nodoc:
           execute "DROP INDEX #{quote_table_name(index_name)}"
         end