Yes , in a map only query your udf will be executed at the mapper side.
I don't know how you can make your udf thread safe. But what I do set the number of reducers to 1 and make sure that I write a query which has both map and reduce. Then the udf will be executed at the reduce phase and suffice my requirement . — Sent from iPhone On Mon, Mar 11, 2013 at 8:43 AM, Shaun Clowes <sclo...@atlassian.com> wrote: > Hi All, > Could anyone describe what the required thread safety for a UDF is? I > understand that one is instantiated for each use of the function in an > expression, but can there be multiple threads executing the methods of a > single UDF object at once? > Thanks, > Shaun
