Re: [HACKERS] Add scale(numeric)

2016-01-05 Thread Alvaro Herrera 
Pavel Stehule wrote:
> Hi
> 
> 2015-11-19 3:27 GMT+01:00 Marko Tiikkaja :
> 
> > Hi,
> >
> > As suggested in 5643125e.1030...@joh.to, here's a patch for extracting
> > the scale out of a numeric.
> >
> > This is 2016-01 CF material, but if someone wants to bas^H^H^Hsay nice
> > things in the meanwhile, feel free.
> >
> 
> This patch is pretty trivial without any possible issues, but I miss a use
> case of this feature.
> 
> Why it should be in Postgres?

This was discussed in the original thread, and it seemed compelling
enough to me; there were no objections raised either.  I couldn't find
any fault in the submitted patch, so pushed.

Thanks,

-- 
Álvaro Herrerahttp://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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Re: [HACKERS] Add scale(numeric)

2015-12-22 Thread Pavel Stehule 
Hi

2015-11-19 3:27 GMT+01:00 Marko Tiikkaja :

> Hi,
>
> As suggested in 5643125e.1030...@joh.to, here's a patch for extracting
> the scale out of a numeric.
>
> This is 2016-01 CF material, but if someone wants to bas^H^H^Hsay nice
> things in the meanwhile, feel free.
>

This patch is pretty trivial without any possible issues, but I miss a use
case of this feature.

Why it should be in Postgres?

Pavel


>
>
> .m
>

[HACKERS] Add scale(numeric)

2015-11-18 Thread Marko Tiikkaja 

Hi,

As suggested in 5643125e.1030...@joh.to, here's a patch for extracting 
the scale out of a numeric.


This is 2016-01 CF material, but if someone wants to bas^H^H^Hsay nice 
things in the meanwhile, feel free.



.m
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***
*** 852,857 
--- 852,870 

 
  
+  scale
+ 
+ scale(numeric)
+
+numeric
+scale of the argument (the number of decimal digits in the 
fractional part)
+scale(8.41)
+2
+   
+ 
+   
+
+ 
   sign
  
  sign(dp or 
numeric)
*** a/src/backend/utils/adt/numeric.c
--- b/src/backend/utils/adt/numeric.c
***
*** 2825,2830  numeric_power(PG_FUNCTION_ARGS)
--- 2825,2847 
PG_RETURN_NUMERIC(res);
  }
  
+ /*
+  * numeric_scale() -
+  *
+  *Returns the scale, i.e. the count of decimal digits in the fractional 
part
+  */
+ Datum
+ numeric_scale(PG_FUNCTION_ARGS)
+ {
+   Numeric num = PG_GETARG_NUMERIC(0);
+ 
+   if (NUMERIC_IS_NAN(num))
+   PG_RETURN_NULL();
+ 
+   PG_RETURN_INT32(NUMERIC_DSCALE(num));
+ }
+ 
+ 
  
  /* --
   *
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***
*** 2361,2366  DESCR("exponentiation");
--- 2361,2368 
  DATA(insert OID = 2169 ( powerPGNSP 
PGUID 12 1 0 0 0 f f f f t f i s 2 0 1700 "1700 1700" _null_ _null_ _null_ 
_null_ _null_  numeric_power _null_ _null_ _null_ ));
  DESCR("exponentiation");
  DATA(insert OID = 1739 ( numeric_powerPGNSP PGUID 12 
1 0 0 0 f f f f t f i s 2 0 1700 "1700 1700" _null_ _null_ _null_ _null_ _null_ 
 numeric_power _null_ _null_ _null_ ));
+ DATA(insert OID =  ( scale  PGNSP PGUID 12 1 0 0 0 f f f f t f i 
s 1 0 23 "1700" _null_ _null_ _null_ _null_ _null_   numeric_scale _null_ 
_null_ _null_ ));
+ DESCR("returns the number of decimal digits in the fractional part");
  DATA(insert OID = 1740 ( numeric  PGNSP PGUID 12 
1 0 0 0 f f f f t f i s 1 0 1700 "23" _null_ _null_ _null_ _null_ _null_ 
int4_numeric _null_ _null_ _null_ ));
  DESCR("convert int4 to numeric");
  DATA(insert OID = 1741 ( log  PGNSP PGUID 14 
1 0 0 0 f f f f t f i s 1 0 1700 "1700" _null_ _null_ _null_ _null_ _null_ 
"select pg_catalog.log(10, $1)" _null_ _null_ _null_ ));
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
***
*** 1022,1027  extern Datum numeric_exp(PG_FUNCTION_ARGS);
--- 1022,1028 
  extern Datum numeric_ln(PG_FUNCTION_ARGS);
  extern Datum numeric_log(PG_FUNCTION_ARGS);
  extern Datum numeric_power(PG_FUNCTION_ARGS);
+ extern Datum numeric_scale(PG_FUNCTION_ARGS);
  extern Datum int4_numeric(PG_FUNCTION_ARGS);
  extern Datum numeric_int4(PG_FUNCTION_ARGS);
  extern Datum int8_numeric(PG_FUNCTION_ARGS);
*** a/src/test/regress/expected/numeric.out
--- b/src/test/regress/expected/numeric.out
***
*** 1852,1854  select log(3.1954752e47, 9.4792021e-73);
--- 1852,1911 
   
-1.51613372350688302142917386143459361608600157692779164475351842333265418126982165
  (1 row)
  
+ --
+ -- Tests for scale()
+ --
+ select scale(numeric 'NaN');
+  scale 
+ ---
+   
+ (1 row)
+ 
+ select scale(NULL::numeric);
+  scale 
+ ---
+   
+ (1 row)
+ 
+ select scale(1.12);
+  scale 
+ ---
+  2
+ (1 row)
+ 
+ select scale(0);
+  scale 
+ ---
+  0
+ (1 row)
+ 
+ select scale(0.00);
+  scale 
+ ---
+  2
+ (1 row)
+ 
+ select scale(1.12345);
+  scale 
+ ---
+  5
+ (1 row)
+ 
+ select scale(110123.12475871856128);
+  scale 
+ ---
+ 14
+ (1 row)
+ 
+ select scale(-1123.12471856128);
+  scale 
+ ---
+ 11
+ (1 row)
+ 
+ select scale(-13.000);
+  scale 
+ ---
+ 15
+ (1 row)
+ 
*** a/src/test/regress/sql/numeric.sql
--- b/src/test/regress/sql/numeric.sql
***
*** 983,985  select log(1.23e-89, 6.4689e45);
--- 983,999 
  select log(0.99923, 4.58934e34);
  select log(1.16, 8.452010e18);
  select log(3.1954752e47, 9.4792021e-73);
+ 
+ --
+ -- Tests for scale()
+ --
+ 
+ select scale(numeric 'NaN');
+ select scale(NULL::numeric);
+ select scale(1.12);
+ select scale(0);
+ select scale(0.00);
+ select scale(1.12345);
+ select scale(110123.12475871856128);
+ select scale(-1123.12471856128);
+ select scale(-13.000);

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