Re: Ryu floating point output patch - Mailing list pgsql-hackers

From Andrew Gierth
Subject Re: Ryu floating point output patch
Date
Msg-id 87won05fed.fsf@news-spur.riddles.org.uk
Whole thread Raw
In response to Re: Ryu floating point output patch  (Donald Dong <xdong@csumb.edu>)
Responses Re: Ryu floating point output patch  (Donald Dong <xdong@csumb.edu>)
List pgsql-hackers
>>>>> "Donald" == Donald Dong <xdong@csumb.edu> writes:

 Donald> I think the previous additional digits behavior still exist
 Donald> in the latest patch. For example:

 Donald> =# set extra_float_digits = 0;
 Donald> SET
 Donald> =# select float4in('1.123456789');
 Donald>  float4in
 Donald> ----------
 Donald>   1.12346
 Donald> (1 row)

 Donald> =# set extra_float_digits = 1;
 Donald> SET
 Donald> =# select float4in('1.123456789');
 Donald>  float4in
 Donald> -----------
 Donald>  1.1234568
 Donald> (1 row)

 Donald> The extra_float_digits is increased by 1, but two digits are
 Donald> added.

That's intentional; this patch takes any value of extra_float_digits
greater than 0 to mean "generate the shortest precise output".

In practice setting extra_float_digits to 1 is rare to nonexistent;
almost all users of extra_float_digits set it to either 3 (to get
precise values), 2 (for historical reasons since we didn't allow more
than 2 in older versions), or less than 0 (to get rounded output for
more convenient display when precision is not required).

-- 
Andrew (irc:RhodiumToad)


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [PROPOSAL] ON DELETE SET NULL () for Foreign Key Constraints
Next
From: Donald Dong
Date:
Subject: Re: Ryu floating point output patch