We want to avoid opening a DB connection in the markdown thread
as its DB connection might live for a long time
(imported from commit 7700b2ca793ee5e9add7f071b92f22a4bf576b3d)
We found that since bugdown processes are threaded, the cost of
doing a db query in a markdown processor is quite high---each
thread must start up a new db connection including a SSL handshake
etc. We should strive to keep our rendering pipeline free of mandatory
DB queries.
(imported from commit 555066bd03da6c681b74ce6137acc264eb41c55d)
Tim Abbott
Luke Faraone
Leo Franchi