On Tue, Feb 4, 2014 at 11:25 AM, Christoph Berg <christoph.b...@credativ.de> wrote: > Re: To Tom Lane 2014-01-08 <20140108094017.ga20...@msgid.df7cb.de> >> What about this patch to mention this gotcha more explicitely in the >> documentation? >> >> diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml >> new file mode 100644 >> index 0386330..968f4a7 >> *** a/doc/src/sgml/datatype.sgml >> --- b/doc/src/sgml/datatype.sgml >> *************** NUMERIC >> *** 689,694 **** >> --- 689,697 ---- >> <literal>0</literal>, the output is the same on every platform >> supported by PostgreSQL. Increasing it will produce output that >> more accurately represents the stored value, but may be unportable. >> + Casts to other numeric datatypes and the <literal>to_char</literal> >> + function are not affected by this setting, it affects only the text >> + representation. >> </para> >> </note> >> > > Anyone for that patch?
Well, the new text kinda recapitulates what the existing text already says. If we're going to clarify, I'd do it like this: The <xref linkend="guc-extra-float-digits"> setting controls the number of extra significant digits included when a floating point value is converted to text for output. It does not affect the results when a floating point number is converted to some other data type or formatted using <literal>to_char</literal>. But frankly I'm inclined to just leave it alone. It says that it affects what happens when the value "is converted to text for output". That's specific and accurate. Granted, someone could misunderstand, but that's true of almost anything we might write, and being too long-winded has costs of its own. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers