Re: Reducing NUMERIC size for 8.3

On 9/24/07, Gregory Stark <stark(at)enterprisedb(dot)com> wrote:
>
>
> We previously discussed compressing the numeric data type for small values:
>
> http://archives.postgresql.org/pgsql-hackers/2007-06/msg00715.php
>
> We didn't do this for 8.3 but in any case Tom did suggest we ought to reverse
> the weight and sign/dscale so we could do this sometime without introducing
> another incompatibility.
>
> I think we also should move the NumericData and declaration to numeric.c and
> make the Numeric type an opaque pointer for the rest of the source tree. That
> will catch any contrib modules or third-party modules which would be broken by
> any new data representation.
>
>
> --- numeric.h 27 Feb 2007 23:48:10 +0000 1.24
> +++ numeric.h 24 Sep 2007 16:07:24 +0100
> @@ -63,8 +63,8 @@
> typedef struct NumericData
> {
> int32 vl_len_; /* varlena header (do not touch directly!) */
> - int16 n_weight; /* Weight of 1st digit */
> uint16 n_sign_dscale; /* Sign + display scale */
> + int16 n_weight; /* Weight of 1st digit */
> char n_data[1]; /* Digits (really array of NumericDigit) */
> } NumericData;

would this break any application pulling a numeric field as binary
over the protocol?

merlin