hadoop-common-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "Hive/LanguageManual/UDF" by ArvindPrabhakar
Date Tue, 13 Jul 2010 22:59:55 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.

The "Hive/LanguageManual/UDF" page has been changed by ArvindPrabhakar.
http://wiki.apache.org/hadoop/Hive/LanguageManual/UDF?action=diff&rev1=44&rev2=45

--------------------------------------------------

  == Built-in Aggregate Functions (UDAF) ==
  The following are built-in aggregate functions are supported in Hive:
  ||<10%>Return Type''' ''' ||<10%>Name(Signature)''' ''' ||Description''' '''
||
- ||bigint ||count(1), count(DISTINCT col [, col]...) ||count(1) returns the number of members
in the group, whereas the count(DISTINCT col) gets the count of distinct values of the columns
in the group ||
+ ||bigint ||count(*), count(expr), count(DISTINCT expr[, expr...]) || count(*) - Returns
the total number of retrieved rows, including rows containing NULL values; count(expr) - Returns
the number of rows for which the supplied expression is non-NULL; count(DISTINCT expr[, expr])
- Returns the number of rows for which the supplied expression(s) are unique and non-NULL.
||
  ||double ||sum(col), sum(DISTINCT col) ||Returns the sum of the elements in the group or
the sum of the distinct values of the column in the group ||
  ||double ||avg(col), avg(DISTINCT col) ||Returns the average of the elements in the group
or the average of the distinct values of the column in the group ||
  ||double ||min(col) ||Returns the minimum of the column in the group ||

Mime
View raw message