Clases
struct	NumericData
'defines'
#define	NUMERIC_MAX_PRECISION 1000
#define	NUMERIC_MAX_DISPLAY_SCALE NUMERIC_MAX_PRECISION
#define	NUMERIC_MIN_DISPLAY_SCALE 0
#define	NUMERIC_MAX_RESULT_SCALE (NUMERIC_MAX_PRECISION * 2)
#define	NUMERIC_MIN_SIG_DIGITS 16
#define	NUMERIC_SIGN_MASK 0xC000
#define	NUMERIC_POS 0x0000
#define	NUMERIC_NEG 0x4000
#define	NUMERIC_NAN 0xC000
#define	NUMERIC_DSCALE_MASK 0x3FFF
#define	NUMERIC_SIGN(n) ((n)->n_sign_dscale & NUMERIC_SIGN_MASK)
#define	NUMERIC_DSCALE(n) ((n)->n_sign_dscale & NUMERIC_DSCALE_MASK)
#define	NUMERIC_IS_NAN(n)
#define	NUMERIC_HDRSZ (sizeof(int32) + sizeof(int16) + sizeof(uint16))
#define	DatumGetNumeric(X) ((Numeric) PG_DETOAST_DATUM(X))
#define	DatumGetNumericCopy(X) ((Numeric) PG_DETOAST_DATUM_COPY(X))
#define	NumericGetDatum(X) PointerGetDatum(X)
#define	PG_GETARG_NUMERIC(n) DatumGetNumeric(PG_GETARG_DATUM(n))
#define	PG_GETARG_NUMERIC_COPY(n) DatumGetNumericCopy(PG_GETARG_DATUM(n))
#define	PG_RETURN_NUMERIC(x) return NumericGetDatum(x)
'typedefs'
typedef struct NumericData	NumericData
typedef NumericData *	Numeric

Documentación de los 'defines'

#define DatumGetNumeric ( X ) ((Numeric) PG_DETOAST_DATUM(X))

#define DatumGetNumericCopy ( X ) ((Numeric) PG_DETOAST_DATUM_COPY(X))

#define NUMERIC_DSCALE ( n ) ((n)->n_sign_dscale & NUMERIC_DSCALE_MASK)

#define NUMERIC_DSCALE_MASK 0x3FFF

#define NUMERIC_HDRSZ (sizeof(int32) + sizeof(int16) + sizeof(uint16))

#define NUMERIC_IS_NAN ( n )

Valor:

(NUMERIC_SIGN(n) != NUMERIC_POS &&      \
                                                         NUMERIC_SIGN(n) != NUMERIC_NEG)

#define NUMERIC_MAX_DISPLAY_SCALE NUMERIC_MAX_PRECISION

#define NUMERIC_MAX_PRECISION 1000

#define NUMERIC_MAX_RESULT_SCALE (NUMERIC_MAX_PRECISION * 2)

#define NUMERIC_MIN_DISPLAY_SCALE 0

#define NUMERIC_MIN_SIG_DIGITS 16

#define NUMERIC_NAN 0xC000

#define NUMERIC_NEG 0x4000

#define NUMERIC_POS 0x0000

#define NUMERIC_SIGN ( n ) ((n)->n_sign_dscale & NUMERIC_SIGN_MASK)

#define NUMERIC_SIGN_MASK 0xC000

#define NumericGetDatum ( X ) PointerGetDatum(X)

#define PG_GETARG_NUMERIC ( n ) DatumGetNumeric(PG_GETARG_DATUM(n))

#define PG_GETARG_NUMERIC_COPY ( n ) DatumGetNumericCopy(PG_GETARG_DATUM(n))

#define PG_RETURN_NUMERIC ( x ) return NumericGetDatum(x)

Documentación de los 'typedefs'