Calculate an aggregate or summary value for row(s). 
  
  Syntax:
   COMP[UTE] [function ... 
      OF {expr|column|alias}...
         ON {expr|column|alias|REPORT|ROW}] 
options:
 OF        The source of the data used in the calculation.
 ON        The event SQL*Plus will use as a break.
functions:
 AVG       Average of non-null values
 COU[NT]   Count of non-null values 
 MAX[IMUM] Maximum value
 MIN[IMUM] Minimum value
 NUM(BER)  Count of rows
 STD       Standard deviation of non-null values
 SUM       Sum of non-null values
 VAR(IANCE)Variance
Entering COMPUTE without any options will list the current definitions.
 
  
  Related Commands:
   
to_char
  SET NUMWIDTH - default width for Number columns
  SET LONG - default width for LONG columns
  SET LONGCHUNKSIZE - default width for LONG columns
  SET MAXDATA - Max width for columns