Postgres: allow enabling prepared statements for specific queries whe…

…n disabled globally.

There is no way to do this otherwise.

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -642,13 +642,14 @@ def execute_and_clear(sql, name, binds, prepare: false)
             raise ActiveRecord::ReadOnlyError, "Write query attempted while in readonly mode: #{sql}"
           end
 
-          if without_prepared_statement?(binds)
+          if prepare
+            result = exec_cache(sql, name, binds)
+          elsif without_prepared_statement?(binds)
             result = exec_no_cache(sql, name, [])
-          elsif !prepare
-            result = exec_no_cache(sql, name, binds)
           else
-            result = exec_cache(sql, name, binds)
+            result = exec_no_cache(sql, name, binds)
           end
+
           ret = yield result
           result.clear
           ret

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

@@ -138,6 +138,17 @@ def test_statement_key_is_logged
       end
     end
 
+    def test_force_prepare_statement
+      @connection.unprepared_statement do
+        @connection.exec_query("SELECT 1::integer", "SQL", [], prepare: true)
+        name = @subscriber.payloads.last[:statement_name]
+        assert name
+        res = @connection.exec_query("EXPLAIN (FORMAT JSON) EXECUTE #{name}(1)")
+        plan = res.column_types["QUERY PLAN"].deserialize res.rows.first.first
+        assert_operator plan.length, :>, 0
+      end
+    end
+
     def test_reconnection_after_actual_disconnection_with_verify
       original_connection_pid = @connection.query("select pg_backend_pid()")