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| author | Bruce Momjian <bruce@momjian.us> | 2008-05-09 15:36:06 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2008-05-09 15:36:06 +0000 |
| commit | 6e3e60095dd4ad882d57468a25f4d76403100b33 (patch) | |
| tree | 9a77fc527258236c9b38c3203c3673fa6a049933 /src/backend/utils/adt/numeric.c | |
| parent | c5f42ce8d5bad857fb9479ea694517738198e0c4 (diff) | |
| download | postgresql-6e3e60095dd4ad882d57468a25f4d76403100b33.tar.gz postgresql-6e3e60095dd4ad882d57468a25f4d76403100b33.zip | |
Update C comments to mention SQL:2003 handling of power return values.
Diffstat (limited to 'src/backend/utils/adt/numeric.c')
| -rw-r--r-- | src/backend/utils/adt/numeric.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c index a8cd22611d3..b4022a7ccf1 100644 --- a/src/backend/utils/adt/numeric.c +++ b/src/backend/utils/adt/numeric.c @@ -14,7 +14,7 @@ * Copyright (c) 1998-2008, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.112 2008/05/08 22:17:54 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.113 2008/05/09 15:36:06 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -1893,8 +1893,9 @@ numeric_power(PG_FUNCTION_ARGS) trunc_var(&arg2_trunc, 0); /* - * Return special SQLSTATE error codes for a few conditions mandated by - * the standard. + * The SQL spec requires that we emit a particular SQLSTATE error code for + * certain error conditions. Specifically, we don't return a divide-by-zero + * error code for 0 ^ -1. */ if ((cmp_var(&arg1, &const_zero) == 0 && cmp_var(&arg2, &const_zero) < 0) || @@ -5283,6 +5284,7 @@ power_var_int(NumericVar *base, int exp, NumericVar *result, int rscale) /* * While 0 ^ 0 can be either 1 or indeterminate (error), we * treat it as 1 because most programming languages do this. + * SQL:2003 also requires a return value of 1. * http://en.wikipedia.org/wiki/Exponentiation#Zero_to_the_zero_power */ set_var_from_var(&const_one, result); |