It's awesome what you can do with Postgres, undeniably, but it seems to me that if you're building a Rails app, for instance, it's an absolute no-brainer to use the brilliant Sunspot gem with Solr. Yes, you have the moderate unpleasantness of setting up Solr and fiddling about with Java and XML files, but it's all pretty painless after that.

I don't know if similarly nice things exist for other web frameworks.

As others have said, what's described in the OP may well be "good enough" for many purposes but it seems like quite a lot of effort to get there.