From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrew Gierth <andrew@tao11.riddles.org.uk>
cc: Andres Freund <andres@anarazel.de>, pgsql-hackers@lists.postgresql.org,
        Thomas Munro <thomas.munro@enterprisedb.com>,
        Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru>
Subject: Re: Performance improvements for src/port/snprintf.c
In-reply-to: <87sh1jaiyq.fsf@news-spur.riddles.org.uk>
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 <87sh1jaiyq.fsf@news-spur.riddles.org.uk>
Comments: In-reply-to Andrew Gierth <andrew@tao11.riddles.org.uk>
	message dated "Sat, 06 Oct 2018 04:10:00 +0100"
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Date: Fri, 05 Oct 2018 23:16:13 -0400
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Andrew Gierth <andrew@tao11.riddles.org.uk> writes:
> So here's a thing: I finally got to doing my performance tests for using
> the Ryu float output code in float[48]out.
> Ryu is so blazing fast that with it, COPY of a table with 2million rows
> of 12 random float8 columns (plus id) becomes FASTER in text mode than
> in binary mode (rather than ~5x slower):

Oh yeah?  Where's the code for this?

> (And yes, I've double-checked the results and they look correct, other
> than the formatting differences. COPY BINARY seems to have a bit more
> overhead than text mode, even for just doing integers, I don't know
> why.)

The per-column overhead is more (length word vs delimiter) and I think
the APIs for send/recv functions are potentially a bit less efficient
too.

			regards, tom lane