Re: Performance improvements for src/port/snprintf.c - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Performance improvements for src/port/snprintf.c
Date
Msg-id 13967.1538795773@sss.pgh.pa.us
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In response to Re: Performance improvements for src/port/snprintf.c  (Andrew Gierth <andrew@tao11.riddles.org.uk>)
Responses Re: Performance improvements for src/port/snprintf.c  (Andrew Gierth <andrew@tao11.riddles.org.uk>)
List pgsql-hackers
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


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