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9389fbd038
NUMERIC_MAX_PRECISION is a purely arbitrary constraint on the precision and scale you can write in a numeric typmod. It might once have had something to do with the allowed range of a typmod-less numeric value, but at least since 9.1 we've allowed, and documented that we allowed, any value that would physically fit in the numeric storage format; which is something over 100000 decimal digits, not 1000. Hence, get rid of numeric_in()'s use of NUMERIC_MAX_PRECISION as a limit on the allowed range of the exponent in scientific-format input. That was especially silly in view of the fact that you can enter larger numbers as long as you don't use 'e' to do it. Just constrain the value enough to avoid localized overflow, and let make_result be the final arbiter of what is too large. Likewise adjust ecpg's equivalent of this code. Also get rid of numeric_recv()'s use of NUMERIC_MAX_PRECISION to limit the number of base-NBASE digits it would accept. That created a dump/restore hazard for binary COPY without doing anything useful; the wire-format limit on number of digits (65535) is about as tight as we would want. In HEAD, also get rid of pg_size_bytes()'s unnecessary intimacy with what the numeric range limit is. That code doesn't exist in the back branches. Per gripe from Aravind Kumar. Back-patch to all supported branches, since they all contain the documentation claim about allowed range of NUMERIC (cf commit cabf5d84b). Discussion: <2895.1471195721@sss.pgh.pa.us>
65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
/*-------------------------------------------------------------------------
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*
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* numeric.h
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* Definitions for the exact numeric data type of Postgres
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*
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* Original coding 1998, Jan Wieck. Heavily revised 2003, Tom Lane.
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*
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* Copyright (c) 1998-2016, PostgreSQL Global Development Group
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*
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* src/include/utils/numeric.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef _PG_NUMERIC_H_
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#define _PG_NUMERIC_H_
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#include "fmgr.h"
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/*
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* Limit on the precision (and hence scale) specifiable in a NUMERIC typmod.
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* Note that the implementation limit on the length of a numeric value is
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* much larger --- beware of what you use this for!
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*/
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#define NUMERIC_MAX_PRECISION 1000
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/*
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* Internal limits on the scales chosen for calculation results
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*/
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#define NUMERIC_MAX_DISPLAY_SCALE NUMERIC_MAX_PRECISION
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#define NUMERIC_MIN_DISPLAY_SCALE 0
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#define NUMERIC_MAX_RESULT_SCALE (NUMERIC_MAX_PRECISION * 2)
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/*
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* For inherently inexact calculations such as division and square root,
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* we try to get at least this many significant digits; the idea is to
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* deliver a result no worse than float8 would.
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*/
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#define NUMERIC_MIN_SIG_DIGITS 16
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/* The actual contents of Numeric are private to numeric.c */
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struct NumericData;
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typedef struct NumericData *Numeric;
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/*
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* fmgr interface macros
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*/
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#define DatumGetNumeric(X) ((Numeric) PG_DETOAST_DATUM(X))
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#define DatumGetNumericCopy(X) ((Numeric) PG_DETOAST_DATUM_COPY(X))
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#define NumericGetDatum(X) PointerGetDatum(X)
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#define PG_GETARG_NUMERIC(n) DatumGetNumeric(PG_GETARG_DATUM(n))
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#define PG_GETARG_NUMERIC_COPY(n) DatumGetNumericCopy(PG_GETARG_DATUM(n))
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#define PG_RETURN_NUMERIC(x) return NumericGetDatum(x)
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/*
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* Utility functions in numeric.c
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*/
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extern bool numeric_is_nan(Numeric num);
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int32 numeric_maximum_size(int32 typmod);
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extern char *numeric_out_sci(Numeric num, int scale);
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extern char *numeric_normalize(Numeric num);
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#endif /* _PG_NUMERIC_H_ */
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