While anyone who is familiar with postgres would never do something as stupid as to delete pg_xlog, according to Google, there appears to be a fair amount of end-users out there having made the irrevocable mistake of deleting the precious directory, a decision made on the assumption that since "it has *log* in the name so it must be unimportant" (http://stackoverflow.com/questions/12897429/what-does-pg-resetxlog-do-and-how-does-it-work).
If we could turn back time, would we have picked "pg_xlog" as the most optimal name for this important directory, or would we have come up with a more user-friendly name?
Personally, I have never had any problems with pg_xlog, but I realize there are quite a few unlucky new users who end up in trouble.
My suggestion is to use "pg_xjournal" instead of "pg_xlog" when new users create a new data directory using initdb, and allow for both directories to exist (exclusive or, i.e. either one or the other, but not both). That way we don't complicate the life for any existing users, all their tools will continue to work who rely on pg_xlog to be named pg_xlog, but only force new users to do a bit of googling when they can't use whatever tool that can't find pg_xlog. When they find out it's an important directory, they can simply create a symlink and their old not yet updated tool will work again.
Thoughts?
+1
Strongly agree - I have had people on my dba course ask about deleting these pesky 'log' directories (obvious confusion/conflation with pg_log ...)! A change of name would help reduce the temptation!
Why is it named pg_log by default anyway? While base and global are not named pg_base (or pg_default) and pg_global ?
If we are going to break things in some release, maybe we should rename them all to have a little more rhyme or reason to them. Or is there already a rhyme or reason I am overlooking?
I would think all the config and human-readable log files/directories should have one prefix (or absence of prefix), and all the internal files/directories with no user serviceable parts should have a different one.