making field sortable in odoo v10
I would like to make base filed to be a sortable field. Only my knowledge is to check indexed then it will work after restarting odoo service. let's say I want to make "_last_updated" filed to indexed field. so that I will tick the indexed check box to make it sortable. then i need to restart the server and update the one of the base module that taking long time.
Is it the right way or can you suggest some suitable way?