This. Answer “pg!” without any clue of what the objective is, and you'll end up with surprises like “oh, you know, this is for a revolutionary concept where people can check in their source code at different stages of development, so that they have a history of their changes and can restore an older version if needed” or “hey, we've followed your expert recommendations but now we're facing some availability issue after a link to our shiny new search engine made the front page of HN and Slashdot”. Migrating from pg to git or SOLR is not really enjoyable, and you can't reuse much of what you've done (unlike when migrating one SQL database to another).