On 20 June 2013 06:45, Craig Ringer <craig@2ndquadrant.com> wrote:
> I think a good starting point would be to use the Intel and IBM
> libraries to implement basic DECIMAL32/64/128 to see if they perform
> better than the gcc builtins tested by Pavel by adapting his extension.
>
> If the performance isn't interesting it may still be worth adding for
> compliance reasons, but if we can only add IEEE-compliant decimal FP by
> using non-SQL-standard type names I don't think that's super useful.
I think we should be adding a datatype that is IEEE compliant, even if
that doesn't have space and/or performance advantages. We might hope
it does, but if not then it may do in the future.
It seems almost certain that the SQL standard would adopt the IEEE
datatypes in the future.
> If
> there are significant performance/space gains to be had, we could
> consider introducing DECIMAL32/64/128 types with the same names used by
> DB2, so people could explicitly choose to use them where appropriate.
Typenames are easily setup if compatibility is required, so thats not a problem.
We'd want to use the name the SQL std people assign.
--Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services