Re: COPY (query) TO file

Greg Stark <gsstark(at)mit(dot)edu> writes:
> PFC <lists(at)peufeu(dot)com> writes:
>> MySQL already does this for INSERT :
>> INSERT INTO x (a,b) VALUES (1,2), (3,4), (5,6)...;

> Does MySQL really let you stream that? Trying to do syntax like that in
> Postgres wouldn't work because the parser would try to build up a parse tree
> for the whole statement before running the command.

A quick look at MySQL's grammar doesn't show any indication that they
don't build a full parse tree too.

The above syntax is SQL-standard, so we ought to support it sometime,
performance benefits or no. I agree it might be tricky to avoid eating
an unreasonable amount of memory for a very long list in Postgres :-(

Supporting VALUES only in INSERT would be relatively trivial BTW,
but the spec actually thinks it should be allowed as a <table spec>
in FROM ...

regards, tom lane