I am sorry to see you stoop to essentially insulting me instead of responding to what I wrote in earnest. Obviously I am well aware that Postgres is capable of concurrency, and indeed even parallelism!
Perhaps you would enjoy reading the first HStore paper, from 2007, and if you remain unconvinced then you could try googling the authors, particularly that “Michael Stonebraker” guy, who sure does seem to know a whole lot about databases!
Of course, a lot has changed since 2007: namely, computers have gone from having 2 cores to 20, SSDs ended up being way cheaper than RAM, and networks got really fast.
