Merge pull request rails#5698 from dougcole/support_postgresql_partit…

…ioning

Support postgresql partitioning by making INSERT RETURNING optional

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

@@ -59,7 +59,7 @@ def exec_query(sql, name = 'SQL', binds = [])
       # Executes insert +sql+ statement in the context of this connection using
       # +binds+ as the bind substitutes. +name+ is logged along with
       # the executed +sql+ statement.
-      def exec_insert(sql, name, binds)
+      def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
         exec_query(sql, name, binds)
       end
 
@@ -87,7 +87,7 @@ def exec_update(sql, name, binds)
       # passed in as +id_value+.
       def insert(arel, name = nil, pk = nil, id_value = nil, sequence_name = nil, binds = [])
         sql, binds = sql_for_insert(to_sql(arel, binds), pk, id_value, sequence_name, binds)
-        value      = exec_insert(sql, name, binds)
+        value      = exec_insert(sql, name, binds, pk, sequence_name)
         id_value || last_inserted_id(value)
       end
 

activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

@@ -226,7 +226,7 @@ def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
       end
       alias :create :insert_sql
 
-      def exec_insert(sql, name, binds)
+      def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
         execute to_sql(sql, binds), name
       end
 

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -17,7 +17,7 @@ def postgresql_connection(config) # :nodoc:
       # Forward any unused config params to PGconn.connect.
       [:statement_limit, :encoding, :min_messages, :schema_search_path,
        :schema_order, :adapter, :pool, :wait_timeout, :template,
-       :reaping_frequency].each do |key|
+       :reaping_frequency, :insert_returning].each do |key|
         conn_params.delete key
       end
       conn_params.delete_if { |k,v| v.nil? }
@@ -258,6 +258,8 @@ def simplified_type(field_type)
     #   <encoding></tt> call on the connection.
     # * <tt>:min_messages</tt> - An optional client min messages that is used in a
     #   <tt>SET client_min_messages TO <min_messages></tt> call on the connection.
+    # * <tt>:insert_returning</tt> - An optional boolean to control the use or <tt>RETURNING</tt> for <tt>INSERT<tt> statements
+    #   defaults to true.
     #
     # Any further options are used as connection parameters to libpq. See
     # http://www.postgresql.org/docs/9.1/static/libpq-connect.html for the
@@ -405,6 +407,7 @@ def initialize(connection, logger, connection_parameters, config)
 
         initialize_type_map
         @local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
+        @use_insert_returning = @config.key?(:insert_returning) ? @config[:insert_returning] : true
       end
 
       # Clears the prepared statements cache.
@@ -666,8 +669,11 @@ def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
           pk = primary_key(table_ref) if table_ref
         end
 
-        if pk
+        if pk && use_insert_returning?
           select_value("#{sql} RETURNING #{quote_column_name(pk)}")
+        elsif pk
+          super
+          last_insert_id_value(sequence_name || default_sequence_name(table_ref, pk))
         else
           super
         end
@@ -782,11 +788,27 @@ def sql_for_insert(sql, pk, id_value, sequence_name, binds)
           pk = primary_key(table_ref) if table_ref
         end
 
-        sql = "#{sql} RETURNING #{quote_column_name(pk)}" if pk
+        if pk && use_insert_returning?
+          sql = "#{sql} RETURNING #{quote_column_name(pk)}"
+        end
 
         [sql, binds]
       end
 
+      def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
+        val = exec_query(sql, name, binds)
+        if !use_insert_returning? && pk
+          unless sequence_name
+            table_ref = extract_table_ref_from_insert_sql(sql)
+            sequence_name = default_sequence_name(table_ref, pk)
+            return val unless sequence_name
+          end
+          last_insert_id_result(sequence_name)
+        else
+          val
+        end
+      end
+
       # Executes an UPDATE query and returns the number of affected tuples.
       def update_sql(sql, name = nil)
         super.cmd_tuples
@@ -1027,7 +1049,9 @@ def client_min_messages=(level)
 
       # Returns the sequence name for a table's primary key or some other specified key.
       def default_sequence_name(table_name, pk = nil) #:nodoc:
-        serial_sequence(table_name, pk || 'id').split('.').last
+        result = serial_sequence(table_name, pk || 'id')
+        return nil unless result
+        result.split('.').last
       rescue ActiveRecord::StatementInvalid
         "#{table_name}_#{pk || 'id'}_seq"
       end
@@ -1235,6 +1259,10 @@ def extract_schema_and_table(name)
         end
       end
 
+      def use_insert_returning?
+        @use_insert_returning
+      end
+
       protected
         # Returns the version of the connected PostgreSQL server.
         def postgresql_version
@@ -1364,8 +1392,15 @@ def configure_connection
 
         # Returns the current ID of a table's sequence.
         def last_insert_id(sequence_name) #:nodoc:
-          r = exec_query("SELECT currval($1)", 'SQL', [[nil, sequence_name]])
-          Integer(r.rows.first.first)
+          Integer(last_insert_id_value(sequence_name))
+        end
+
+        def last_insert_id_value(sequence_name)
+          last_insert_id_result(sequence_name).rows.first.first
+        end
+
+        def last_insert_id_result(sequence_name) #:nodoc:
+          exec_query("SELECT currval($1)", 'SQL', [[nil, sequence_name]])
         end
 
         # Executes a SELECT query and returns the results, performing any data type

activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb

@@ -49,6 +49,33 @@ def test_insert_sql_with_no_space_after_table_name
         assert_equal expect, id
       end
 
+      def test_insert_sql_with_returning_disabled
+        connection = connection_without_insert_returning
+        id = connection.insert_sql("insert into postgresql_partitioned_table_parent (number) VALUES (1)")
+        expect = connection.query('select max(id) from postgresql_partitioned_table_parent').first.first
+        assert_equal expect, id
+      end
+
+      def test_exec_insert_with_returning_disabled
+        connection = connection_without_insert_returning
+        result = connection.exec_insert("insert into postgresql_partitioned_table_parent (number) VALUES (1)", nil, [], 'id', 'postgresql_partitioned_table_parent_id_seq')
+        expect = connection.query('select max(id) from postgresql_partitioned_table_parent').first.first
+        assert_equal expect, result.rows.first.first
+      end
+
+      def test_exec_insert_with_returning_disabled_and_no_sequence_name_given
+        connection = connection_without_insert_returning
+        result = connection.exec_insert("insert into postgresql_partitioned_table_parent (number) VALUES (1)", nil, [], 'id')
+        expect = connection.query('select max(id) from postgresql_partitioned_table_parent').first.first
+        assert_equal expect, result.rows.first.first
+      end
+
+      def test_sql_for_insert_with_returning_disabled
+        connection = connection_without_insert_returning
+        result = connection.sql_for_insert('sql', nil, nil, nil, 'binds')
+        assert_equal ['sql', 'binds'], result
+      end
+
       def test_serial_sequence
         assert_equal 'public.accounts_id_seq',
           @connection.serial_sequence('accounts', 'id')
@@ -204,6 +231,10 @@ def insert(ctx, data)
 
         ctx.exec_insert(sql, 'SQL', binds)
       end
+
+      def connection_without_insert_returning
+        ActiveRecord::Base.postgresql_connection(ActiveRecord::Base.configurations['arunit'].merge(:insert_returning => false))
+      end
     end
   end
 end

activerecord/test/schema/postgresql_specific_schema.rb

@@ -1,15 +1,17 @@
 ActiveRecord::Schema.define do
 
   %w(postgresql_tsvectors postgresql_hstores postgresql_arrays postgresql_moneys postgresql_numbers postgresql_times postgresql_network_addresses postgresql_bit_strings
-      postgresql_oids postgresql_xml_data_type defaults geometrics postgresql_timestamp_with_zones).each do |table_name|
-    execute "DROP TABLE  IF EXISTS #{quote_table_name table_name}"
+      postgresql_oids postgresql_xml_data_type defaults geometrics postgresql_timestamp_with_zones postgresql_partitioned_table postgresql_partitioned_table_parent).each do |table_name|
+    execute "DROP TABLE IF EXISTS #{quote_table_name table_name}"
   end
 
   execute 'DROP SEQUENCE IF EXISTS companies_nonstd_seq CASCADE'
   execute 'CREATE SEQUENCE companies_nonstd_seq START 101 OWNED BY companies.id'
   execute "ALTER TABLE companies ALTER COLUMN id SET DEFAULT nextval('companies_nonstd_seq')"
   execute 'DROP SEQUENCE IF EXISTS companies_id_seq'
 
+  execute 'DROP FUNCTION IF EXISTS partitioned_insert_trigger()'
+
   %w(accounts_id_seq developers_id_seq projects_id_seq topics_id_seq customers_id_seq orders_id_seq).each do |seq_name|
     execute "SELECT setval('#{seq_name}', 100)"
   end
@@ -125,6 +127,29 @@
   );
 _SQL
 
+  execute <<_SQL
+  CREATE TABLE postgresql_partitioned_table_parent (
+    id SERIAL PRIMARY KEY,
+    number integer
+  );
+  CREATE TABLE postgresql_partitioned_table ( )
+    INHERITS (postgresql_partitioned_table_parent);
+
+  CREATE OR REPLACE FUNCTION partitioned_insert_trigger()
+  RETURNS TRIGGER AS $$
+  BEGIN
+    INSERT INTO postgresql_partitioned_table VALUES (NEW.*);
+    RETURN NULL;
+  END;
+  $$
+  LANGUAGE plpgsql;
+
+  CREATE TRIGGER insert_partitioning_trigger
+    BEFORE INSERT ON postgresql_partitioned_table_parent
+    FOR EACH ROW EXECUTE PROCEDURE partitioned_insert_trigger();
+_SQL
+
+
   begin
     execute <<_SQL
     CREATE TABLE postgresql_xml_data_type (