-Will this UDF always execute on a single reducer ?
Vaibhav Jain 2014-03-01, 03:57
I have written a custom UDF that I want to be executed on a single reducer
when I am using it in a query. Following is the the query and I want to
confirm whether this would always always execute the UDF on a single
reducer (assuming the ORDER BY would send all the rows to a single
*SELECT UDF(<col>) AS alias from *
*( SELECT <col> *
* FROM <table> TABLESAMPLE (x PERCENT) *
* ORDER BY <col> )*
*ORDER BY alias;*
Is it a possibility that the UDF is executed on a mapper?