This page, Setting up automatic Smart Search indexing, from the Joomla! Documentation states that Smart Search automatically indexes content once it has been amended. However, I've found on a site I'm working on that this isn't the case - I have to manually index content for it to appear, or set up a cron job.
How is smart search automatic indexing meant to work? Is it via the 'Content - Smart Search' plugin via a plugin hook? If so, do any other config items need to be set to get it working?