Re: SendRowDescriptionMessage() is slow for queries with a lot of columns

Hi,

Attached is a revised version of this patchset. I'd like to get some
input on two points:

1) Does anybody have a better idea than the static buffer in
SendRowDescriptionMessage()? That's not particularly pretty, but
there's not really a convenient stringbuffer to use when called from
exec_describe_portal_message(). We could instead create a local
buffer for exec_describe_portal_message().

An alternative idea would be to have one reeusable buffer created for
each transaction command, but I'm not sure that's really better.

2) There's a lot of remaining pq_sendint() callers in other parts of the
tree. If others are ok with that, I'd do a separate pass over them.
I'd say that even after doing that, we should keep pq_sendint(),
because a lot of extension code is using that.

3) The use of restrict, with a configure based fallback, is something
we've not done before, but it's C99 and delivers significantly more
efficient code. Any arguments against?

Regards,

Andres