*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 852,857 ****
--- 852,870 ----
        <row>
         <entry>
          <indexterm>
+          <primary>scale</primary>
+         </indexterm>
+         <literal><function>scale(<type>numeric</type>)</function></literal>
+        </entry>
+        <entry><type>numeric</type></entry>
+        <entry>scale of the argument (the number of decimal digits in the fractional part)</entry>
+        <entry><literal>scale(8.41)</literal></entry>
+        <entry><literal>2</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <indexterm>
           <primary>sign</primary>
          </indexterm>
          <literal><function>sign(<type>dp</type> or <type>numeric</type>)</function></literal>
*** 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 ( power					PGNSP 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_power			PGNSP 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 = 8888 ( 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(-13.000000000000000);
+  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(1.000016, 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(-13.000000000000000);