1 files changed, 42 insertions, 3 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 209553b26e..2bb2557efd 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -478,7 +478,7 @@ module ActiveRecord
       def initialize(connection, logger, connection_parameters, config)
         super(connection, logger)
 
-        if config.fetch(:prepared_statements) { true }
+        if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
           @visitor = Arel::Visitors::PostgreSQL.new self
         else
           @visitor = BindSubstitution.new self
@@ -492,7 +492,7 @@ module ActiveRecord
 
         connect
         @statements = StatementPool.new @connection,
-                                        config.fetch(:statement_limit) { 1000 }
+                                        self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 })
 
         if postgresql_version < 80200
           raise "Your version of PostgreSQL (#{postgresql_version}) is too old, please upgrade!"
@@ -500,7 +500,7 @@ module ActiveRecord
 
         initialize_type_map
         @local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
-        @use_insert_returning = @config.key?(:insert_returning) ? @config[:insert_returning] : true
+        @use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
       end
 
       # Clears the prepared statements cache.
@@ -575,11 +575,45 @@ module ActiveRecord
         true
       end
 
+      # Returns true if pg > 9.2
+      def supports_extensions?
+        postgresql_version >= 90200
+      end
+
       # Range datatypes weren't introduced until PostgreSQL 9.2
       def supports_ranges?
         postgresql_version >= 90200
       end
 
+      def enable_extension(name)
+        exec_query("CREATE EXTENSION IF NOT EXISTS #{name}").tap {
+          reload_type_map
+        }
+      end
+
+      def disable_extension(name)
+        exec_query("DROP EXTENSION IF EXISTS #{name} CASCADE").tap {
+          reload_type_map
+        }
+      end
+
+      def extension_enabled?(name)
+        if supports_extensions?
+          res = exec_query "SELECT EXISTS(SELECT * FROM pg_available_extensions WHERE name = '#{name}' AND installed_version IS NOT NULL)",
+            'SCHEMA'
+          res.column_types['exists'].type_cast res.rows.first.first
+        end
+      end
+
+      def extensions
+        if supports_extensions?
+          res = exec_query "SELECT extname from pg_extension", "SCHEMA"
+          res.rows.map { |r| res.column_types['extname'].type_cast r.first }
+        else
+          super
+        end
+      end
+
       # Returns the configured supported identifier length supported by PostgreSQL
       def table_alias_length
         @table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i
@@ -645,6 +679,11 @@ module ActiveRecord
 
       private
 
+        def reload_type_map
+          OID::TYPE_MAP.clear
+          initialize_type_map
+        end
+
         def initialize_type_map
           result = execute('SELECT oid, typname, typelem, typdelim, typinput FROM pg_type', 'SCHEMA')
           leaves, nodes = result.partition { |row| row['typelem'] == '0' }