Re: [HACKERS] Our FLOAT(p) precision does not conform to spec - Mailing list pgsql-sql

From Shridhar Daithankar
Subject Re: [HACKERS] Our FLOAT(p) precision does not conform to spec
Date
Msg-id 3EEF0AF4.16718.1AEA03@localhost
Whole thread Raw
In response to Our FLOAT(p) precision does not conform to spec  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-sql
On 16 Jun 2003 at 18:15, Tom Lane wrote:
> This is a straightforward change and would not break pg_dump files,
> since fortunately pg_dump always references the underlying types and
> never refers to anything as FLOAT(p).  But I wonder whether it is
> likely to break many existing applications.  There is a hazard of some
> existing app asking for (what it thinks is) float8 and getting float4
> instead.

Especially apps. which rely on number(3) not to accept anything greate than +/-
999.

I hate the syntax of putting decimal digits as range checkers in SQL field. But 
oracle does that and consequently lot of oracle apps rely on it. I won't be 
surprised if float(p) notion brings same assurance to such app developers.

I think this would become and FAQ after changes are implemented. Who reads 
release notes anyway?..:-)
> Is it worth trying to provide some sort of backwards-compatibility mode?
> We could imagine adding a GUC variable to select binary or decimal
> precision, but I really don't want to.  It would increase the amount of
> work needed by more than an order of magnitude, and this problem doesn't
> seem worth it.  I'd rather just list this under Incompatibilities in the
> 7.4 release notes.

Is it possible to have float-2(p) and float-10(p)? Would it be adding code 
sections instead of replacing it?

That would be cleaner than GUC variable. Everything defaults to float-10(p) for 
backward compatibility for a period of a release and in 7.5, it gets switched 
to float-2(p). In the meantime, the behaviour remains available who cares to 
read the docs and notes.

Just a thought..

ByeShridhar

--
Genderplex, n.:    The predicament of a person in a restaurant who is unable to    
determine his or her designated restroom (e.g., turtles and tortoises).        -- 
Rich Hall, "Sniglets"



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