Bruce Momjian <maillist@candle.pha.pa.us> writes:
>> Efficiency is all, along with (probably) the backend being unhappy
>> getting *only* a comment and no query.
> That is fixed now.
Is it? postgres.c treats an all-whitespace input as an empty query,
but if you pass it a comment and nothing else it will cycle the parser/
planner/executor, and I'm not sure every phase of that process behaves
reasonably on empty input. Also, that path will not produce the
"empty query" response code that you get from all-whitespace input.
I *think* libpq doesn't depend on that anymore, but other frontend
libraries might...
regards, tom lane