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numeric.h
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1 /*-------------------------------------------------------------------------
2  *
3  * numeric.h
4  * Definitions for the exact numeric data type of Postgres
5  *
6  * Original coding 1998, Jan Wieck. Heavily revised 2003, Tom Lane.
7  *
8  * Copyright (c) 1998-2017, PostgreSQL Global Development Group
9  *
10  * src/include/utils/numeric.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef _PG_NUMERIC_H_
15 #define _PG_NUMERIC_H_
16 
17 #include "fmgr.h"
18 
19 /*
20  * Limit on the precision (and hence scale) specifiable in a NUMERIC typmod.
21  * Note that the implementation limit on the length of a numeric value is
22  * much larger --- beware of what you use this for!
23  */
24 #define NUMERIC_MAX_PRECISION 1000
25 
26 /*
27  * Internal limits on the scales chosen for calculation results
28  */
29 #define NUMERIC_MAX_DISPLAY_SCALE NUMERIC_MAX_PRECISION
30 #define NUMERIC_MIN_DISPLAY_SCALE 0
31 
32 #define NUMERIC_MAX_RESULT_SCALE (NUMERIC_MAX_PRECISION * 2)
33 
34 /*
35  * For inherently inexact calculations such as division and square root,
36  * we try to get at least this many significant digits; the idea is to
37  * deliver a result no worse than float8 would.
38  */
39 #define NUMERIC_MIN_SIG_DIGITS 16
40 
41 /* The actual contents of Numeric are private to numeric.c */
42 struct NumericData;
43 typedef struct NumericData *Numeric;
44 
45 /*
46  * fmgr interface macros
47  */
48 
49 #define DatumGetNumeric(X) ((Numeric) PG_DETOAST_DATUM(X))
50 #define DatumGetNumericCopy(X) ((Numeric) PG_DETOAST_DATUM_COPY(X))
51 #define NumericGetDatum(X) PointerGetDatum(X)
52 #define PG_GETARG_NUMERIC(n) DatumGetNumeric(PG_GETARG_DATUM(n))
53 #define PG_GETARG_NUMERIC_COPY(n) DatumGetNumericCopy(PG_GETARG_DATUM(n))
54 #define PG_RETURN_NUMERIC(x) return NumericGetDatum(x)
55 
56 /*
57  * Utility functions in numeric.c
58  */
59 extern bool numeric_is_nan(Numeric num);
61 extern char *numeric_out_sci(Numeric num, int scale);
62 extern char *numeric_normalize(Numeric num);
63 
64 #endif /* _PG_NUMERIC_H_ */
char * numeric_out_sci(Numeric num, int scale)
Definition: numeric.c:719
int scale
Definition: pgbench.c:106
struct NumericData * Numeric
Definition: numeric.h:43
signed int int32
Definition: c.h:253
char * numeric_normalize(Numeric num)
Definition: numeric.c:746
int32 numeric_maximum_size(int32 typmod)
Definition: numeric.c:680
bool numeric_is_nan(Numeric num)
Definition: numeric.c:669