Dear Wiki user,

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

The "Hive/DeveloperGuide/UDTF" page has been changed by PaulYang.
http://wiki.apache.org/hadoop/Hive/DeveloperGuide/UDTF?action=diff&rev1=3&rev2=4

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

  
  == GenericUDTF Interface ==
  
- A custom UDTF can be created by extendign the GenericUDTF abstract class then 
implementing the {{{initialize}}}, {{{process}}}, and possibly {{{close}}} 
methods. The {{{initialize}}} method is called by Hive to notify the UDTF the 
argument types to expect. The UDTF must then return an object inspector 
corresponding to the row objects that the UDTF will generate. Once 
{{initialize()}} has been called, Hive will give rows to the UDTF using the 
{{{process()}}} method. While in {{{process()}}}, the UDTF can produce and 
forward rows to other operators by calling {{{forward()}}}. Lastly, Hive will 
call the {{{close()}}} method when all the rows have processed by the UDTF.
+ A custom UDTF can be created by extendign the GenericUDTF abstract class then 
implementing the {{{initialize}}}, {{{process}}}, and possibly {{{close}}} 
methods. The {{{initialize}}} method is called by Hive to notify the UDTF the 
argument types to expect. The UDTF must then return an object inspector 
corresponding to the row objects that the UDTF will generate. Once 
{{{initialize()}} has been called, Hive will give rows to the UDTF using the 
{{{process()}}} method. While in {{{process()}}}, the UDTF can produce and 
forward rows to other operators by calling {{{forward()}}}. Lastly, Hive will 
call the {{{close()}}} method when all the rows have processed by the UDTF.
  
  UDTF Example:
  

Reply via email to