Allowing partial survey completion - when to save to DB

[asydaykem]

I'm building a simple survey, consisting of several pages with questions that all have multi-choice answers: radio buttons and checkboxesThe end result required are records in a MySQL table, one for each answer selected.And we want to make it so that you can quit halfway through and come back later to complete.My first thought was to simply save to the database (via AJAX) on every click of a checkbox/radio button. But I'm worried about performance and load on the server. However the only alternative is to save to a session or JS array then save them when they click 'next'. This isn't as ideal but would be much lesser load.Any suggestions?