Horton

Re: Ryu floating point output patch

Andrew Gierth <andrew@tao11.riddles.org.uk>

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From: Andrew Gierth <andrew@tao11.riddles.org.uk>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, pgsql-hackers@postgresql.org, "David G. Johnston" <david.g.johnston@gmail.com>, Donald Dong <xdong@csumb.edu>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Chapman Flack <chap@anastigmatix.net>
Date: 2019-02-17T23:15:42Z
Lists: pgsql-hackers 
>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:

 > Andrew Dunstan <andrew.dunstan@2ndquadrant.com> writes:
 >> Here's a patch without docco. How much do we actually want to
 >> document this? I'm not sure it has any great value outside of
 >> cross-version upgrade testing.

 Tom> I think we have to document it, but it can be fairly terse perhaps.

 Tom> 	Use the specified value of extra_float_digits when dumping
 Tom> 	floating-point data, rather than pg_dump's default.

 Tom> I don't think we need to go into detail about when/why you might
 Tom> want to use it; I can see people thinking of their own reasons.

It should probably at least say that (a) the default is to dump with the
maximum available precision, and at least hint at (b) that ordinary use
doesn't require the option. We shouldn't mislead people into thinking
they need it when they don't.

-- 
Andrew (irc:RhodiumToad)

Commits

  1. Provide an extra-float-digits setting for pg_dump / pg_dumpall

  2. Change floating-point output format for improved performance.

  3. Use strtof() and not strtod() for float4 input.