Re: [HACKERS] numeric data type on 6.5

Thomas Lockhart wrote:

> The float8_numeric() code already had checked for NULL and NaN, so I
> think this does not lose functionality. What do you think Jan? Should
> I make the change? Or is there another way??

Think it's O.K. - commit the changes.

The other way would be to enhance the NUMERIC input function
to read exponential notation. But I wouldn't do this now
because I've planned to someday implement NUMERIC again from
scratch.

The current implementation has a packed storage format and
the arithmetic operations are based on a character format
(each digit is stored in one byte). After thinking about it
I discovered, that storing the value internally in short
int's (16 bit) and base 10000 would have some advantages.

1. No need to pack/unpack storage format for computations.

2. One arithmetic operation in the innermost loops (only
add/subtract are really implemented) mucks with 4 digits
at a time.

The disadvantages are small. Base 10000 to base 10 (decimal)
conversion is easily to parse/print. Only rounding functions
will be a little tricky. I think the speedup gained from
adding/subtracting 4 digits per loop iteration will be worth
the efford.

Jan

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