Re: auto_explain sample rate

Craig Ringer <craig@2ndquadrant.com> writes:
> It's sometimes desirable to collect auto_explain data with ANALYZE in order
> to track down hard-to-reproduce issues, but the performance impacts can be
> pretty hefty on the DB.

> I'm inclined to add a sample rate to auto_explain so that it can trigger
> only on x percent of queries,

That sounds reasonable ...

> and also add a sample test hook that can be
> used to target statements of interest more narrowly (using a C hook
> function).

You'd have to be pretty desperate, *and* knowledgeable, to write a
C function for that.  Can't we invent something a bit more user-friendly
for the purpose?  No idea what it should look like though.
        regards, tom lane