Re: Re: [Oledb-dev] double precision error with pg linux server, but not with windows pg server

Shachar Shemesh <shachar(at)shemesh(dot)biz> writes:
> Tom Lane wrote:
>> No, not unless you can make the case why this handles NaNs and
>> denormalized numbers compatibly across platforms...
>>
> NaNs and infinite (plus and minus) should not be a problem.

Really? Need I point out that these concepts, let alone their
representation, are not standardized in non-IEEE float implementations?

> I'm not sure what denormalized numbers are.

You should find out before proposing representation replacements for
floats.

> What is the scenario in which you would want to tell them apart?
> Likewise, would you really want to tell +0 and -0 apart?

There are competent authorities --- for instance, the guys who created
the IEEE float standard --- who think it's worth distinguishing them.
IIRC (it's been fifteen or so years since I did any serious numerical
analysis) the arguments in favor have mostly to do with preserving
maximal accuracy for intermediate results in a series of calculations.
So maybe you could claim that these arguments are not so relevant to
storage in a database. But personally I don't think it's the province
of a database to decide that it need not accurately preserve the data
it's given to store.

regards, tom lane